diff --git a/Makefile b/Makefile
index ad03a3964..e0fd4e6c0 100644
--- a/Makefile
+++ b/Makefile
@@ -15,6 +15,7 @@ init:
 lint:
 	flake8 moto
 	black --check moto/ tests/
+	pylint -j 0 tests
 
 format:
 	black moto/ tests/
diff --git a/requirements-tests.txt b/requirements-tests.txt
index 847ce539e..350da8111 100644
--- a/requirements-tests.txt
+++ b/requirements-tests.txt
@@ -2,3 +2,4 @@ pytest
 pytest-cov
 sure==1.4.11
 freezegun
+pylint
diff --git a/setup.cfg b/setup.cfg
index b7aa23edf..f907977e3 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -7,3 +7,8 @@ markers =
 
 [coverage:run]
 relative_files = True
+
+[pylint.'MESSAGES CONTROL']
+disable = W,C,R,E
+# Check we have any tests with duplicate names (causing them to be skipped)
+enable = function-redefined
diff --git a/tests/test_cloudformation/test_cloudformation_stack_crud.py b/tests/test_cloudformation/test_cloudformation_stack_crud.py
index 1725be0f6..9c1a723a0 100644
--- a/tests/test_cloudformation/test_cloudformation_stack_crud.py
+++ b/tests/test_cloudformation/test_cloudformation_stack_crud.py
@@ -5,6 +5,7 @@ import json
 
 import boto
 import boto3
+import boto.dynamodb2
 import boto.iam
 import boto.s3
 import boto.s3.key
@@ -20,8 +21,7 @@ from moto import (
     mock_s3_deprecated,
     mock_route53_deprecated,
     mock_iam_deprecated,
-    mock_dynamodb2,
-    mock_cloudformation,
+    mock_dynamodb2_deprecated,
 )
 from moto.cloudformation import cloudformation_backends
 
@@ -73,6 +73,7 @@ dummy_template4 = {
 dummy_template_json = json.dumps(dummy_template)
 dummy_template_json2 = json.dumps(dummy_template2)
 dummy_template_json3 = json.dumps(dummy_template3)
+dummy_template_json4 = json.dumps(dummy_template4)
 
 
 @mock_cloudformation_deprecated
@@ -213,32 +214,17 @@ def test_describe_stack_by_stack_id():
     stack_by_id.stack_name.should.equal("test_stack")
 
 
-@mock_dynamodb2
+@mock_dynamodb2_deprecated
 @mock_cloudformation_deprecated
 def test_delete_stack_dynamo_template():
     conn = boto.connect_cloudformation()
-    dynamodb_client = boto3.client("dynamodb", region_name="us-east-1")
-    conn.create_stack("test_stack", template_body=dummy_template4)
-    table_desc = dynamodb_client.list_tables()
-    len(table_desc.get("TableNames")).should.equal(1)
+    db_conn = boto.dynamodb2.connect_to_region("us-east-1")
+    #
+    conn.create_stack("test_stack", template_body=dummy_template_json4)
+    db_conn.list_tables()["TableNames"].should.have.length_of(1)
+    #
     conn.delete_stack("test_stack")
-    table_desc = dynamodb_client.list_tables()
-    len(table_desc.get("TableNames")).should.equal(0)
-    conn.create_stack("test_stack", template_body=dummy_template4)
-
-
-@mock_dynamodb2
-@mock_cloudformation
-def test_delete_stack_dynamo_template():
-    conn = boto3.client("cloudformation", region_name="us-east-1")
-    dynamodb_client = boto3.client("dynamodb", region_name="us-east-1")
-    conn.create_stack(StackName="test_stack", TemplateBody=json.dumps(dummy_template4))
-    table_desc = dynamodb_client.list_tables()
-    len(table_desc.get("TableNames")).should.equal(1)
-    conn.delete_stack(StackName="test_stack")
-    table_desc = dynamodb_client.list_tables()
-    len(table_desc.get("TableNames")).should.equal(0)
-    conn.create_stack(StackName="test_stack", TemplateBody=json.dumps(dummy_template4))
+    db_conn.list_tables()["TableNames"].should.have.length_of(0)
 
 
 @mock_cloudformation_deprecated
diff --git a/tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py b/tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py
index 0ffb71fdc..1c2c546cd 100644
--- a/tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py
+++ b/tests/test_cloudformation/test_cloudformation_stack_crud_boto3.py
@@ -11,9 +11,9 @@ import sure  # noqa
 
 import pytest
 
-from moto import mock_cloudformation, mock_s3, mock_sqs, mock_ec2
+from moto import mock_cloudformation, mock_dynamodb2, mock_s3, mock_sqs, mock_ec2
 from moto.core import ACCOUNT_ID
-from .test_cloudformation_stack_crud import dummy_template_json2
+from .test_cloudformation_stack_crud import dummy_template_json2, dummy_template_json4
 from tests import EXAMPLE_AMI_ID
 
 dummy_template = {
@@ -1681,3 +1681,17 @@ def test_boto3_create_duplicate_stack():
         cf_conn.create_stack(
             StackName="test_stack", TemplateBody=dummy_template_json,
         )
+
+
+@mock_dynamodb2
+@mock_cloudformation
+def test_delete_stack_dynamo_template():
+    conn = boto3.client("cloudformation", region_name="us-east-1")
+    dynamodb_client = boto3.client("dynamodb", region_name="us-east-1")
+    conn.create_stack(StackName="test_stack", TemplateBody=dummy_template_json4)
+    table_desc = dynamodb_client.list_tables()
+    len(table_desc.get("TableNames")).should.equal(1)
+    conn.delete_stack(StackName="test_stack")
+    table_desc = dynamodb_client.list_tables()
+    len(table_desc.get("TableNames")).should.equal(0)
+    conn.create_stack(StackName="test_stack", TemplateBody=dummy_template_json4)
diff --git a/tests/test_dynamodb2/test_dynamodb.py b/tests/test_dynamodb2/test_dynamodb.py
index 7085c0d67..2efcf6e26 100644
--- a/tests/test_dynamodb2/test_dynamodb.py
+++ b/tests/test_dynamodb2/test_dynamodb.py
@@ -475,58 +475,6 @@ def test_item_add_long_string_range_key_exception():
     )
 
 
-@mock_dynamodb2
-def test_item_add_long_string_range_key_exception():
-    name = "TestTable"
-    conn = boto3.client(
-        "dynamodb",
-        region_name="us-west-2",
-        aws_access_key_id="ak",
-        aws_secret_access_key="sk",
-    )
-    conn.create_table(
-        TableName=name,
-        KeySchema=[
-            {"AttributeName": "forum_name", "KeyType": "HASH"},
-            {"AttributeName": "ReceivedTime", "KeyType": "RANGE"},
-        ],
-        AttributeDefinitions=[
-            {"AttributeName": "forum_name", "AttributeType": "S"},
-            {"AttributeName": "ReceivedTime", "AttributeType": "S"},
-        ],
-        ProvisionedThroughput={"ReadCapacityUnits": 5, "WriteCapacityUnits": 5},
-    )
-
-    conn.put_item(
-        TableName=name,
-        Item={
-            "forum_name": {"S": "LOLCat Forum"},
-            "subject": {"S": "Check this out!"},
-            "Body": {"S": "http://url_to_lolcat.gif"},
-            "SentBy": {"S": "someone@somewhere.edu"},
-            "ReceivedTime": {"S": "x" * RANGE_KEY_MAX_LENGTH},
-        },
-    )
-
-    with pytest.raises(ClientError) as ex:
-        conn.put_item(
-            TableName=name,
-            Item={
-                "forum_name": {"S": "LOLCat Forum"},
-                "subject": {"S": "Check this out!"},
-                "Body": {"S": "http://url_to_lolcat.gif"},
-                "SentBy": {"S": "someone@somewhere.edu"},
-                "ReceivedTime": {"S": "x" * (RANGE_KEY_MAX_LENGTH + 1)},
-            },
-        )
-
-    ex.value.response["Error"]["Code"].should.equal("ValidationException")
-    ex.value.response["ResponseMetadata"]["HTTPStatusCode"].should.equal(400)
-    ex.value.response["Error"]["Message"].should.equal(
-        "One or more parameter values were invalid: Aggregated size of all range keys has exceeded the size limit of 1024 bytes"
-    )
-
-
 @mock_dynamodb2
 def test_update_item_with_long_string_hash_key_exception():
     name = "TestTable"
@@ -838,79 +786,12 @@ def test_basic_projection_expression_using_get_item():
     )
 
 
-@mock_dynamodb2
-def test_basic_projection_expressions_using_query():
-    dynamodb = boto3.resource("dynamodb", region_name="us-east-1")
-
-    # Create the DynamoDB table.
-    table = dynamodb.create_table(
-        TableName="users",
-        KeySchema=[
-            {"AttributeName": "forum_name", "KeyType": "HASH"},
-            {"AttributeName": "subject", "KeyType": "RANGE"},
-        ],
-        AttributeDefinitions=[
-            {"AttributeName": "forum_name", "AttributeType": "S"},
-            {"AttributeName": "subject", "AttributeType": "S"},
-        ],
-        ProvisionedThroughput={"ReadCapacityUnits": 5, "WriteCapacityUnits": 5},
-    )
-    table = dynamodb.Table("users")
-
-    table.put_item(
-        Item={"forum_name": "the-key", "subject": "123", "body": "some test message"}
-    )
-
-    table.put_item(
-        Item={
-            "forum_name": "not-the-key",
-            "subject": "123",
-            "body": "some other test message",
-        }
-    )
-    # Test a query returning all items
-    results = table.query(
-        KeyConditionExpression=Key("forum_name").eq("the-key"),
-        ProjectionExpression="body, subject",
-    )
-
-    assert "body" in results["Items"][0]
-    assert results["Items"][0]["body"] == "some test message"
-    assert "subject" in results["Items"][0]
-
-    table.put_item(
-        Item={
-            "forum_name": "the-key",
-            "subject": "1234",
-            "body": "yet another test message",
-        }
-    )
-
-    results = table.query(
-        KeyConditionExpression=Key("forum_name").eq("the-key"),
-        ProjectionExpression="body",
-    )
-
-    assert "body" in results["Items"][0]
-    assert "subject" not in results["Items"][0]
-    assert results["Items"][0]["body"] == "some test message"
-    assert "body" in results["Items"][1]
-    assert "subject" not in results["Items"][1]
-    assert results["Items"][1]["body"] == "yet another test message"
-
-    # The projection expression should not remove data from storage
-    results = table.query(KeyConditionExpression=Key("forum_name").eq("the-key"))
-    assert "subject" in results["Items"][0]
-    assert "body" in results["Items"][1]
-    assert "forum_name" in results["Items"][1]
-
-
 @mock_dynamodb2
 def test_basic_projection_expressions_using_scan():
     dynamodb = boto3.resource("dynamodb", region_name="us-east-1")
 
     # Create the DynamoDB table.
-    table = dynamodb.create_table(
+    dynamodb.create_table(
         TableName="users",
         KeySchema=[
             {"AttributeName": "forum_name", "KeyType": "HASH"},
@@ -957,10 +838,11 @@ def test_basic_projection_expressions_using_scan():
         FilterExpression=Key("forum_name").eq("the-key"), ProjectionExpression="body"
     )
 
-    assert "body" in results["Items"][0]
+    bodies = [item["body"] for item in results["Items"]]
+    bodies.should.contain("some test message")
+    bodies.should.contain("yet another test message")
     assert "subject" not in results["Items"][0]
     assert "forum_name" not in results["Items"][0]
-    assert "body" in results["Items"][1]
     assert "subject" not in results["Items"][1]
     assert "forum_name" not in results["Items"][1]
 
@@ -1151,65 +1033,6 @@ def test_nested_projection_expression_using_query():
     )
 
 
-@mock_dynamodb2
-def test_basic_projection_expressions_using_scan():
-    dynamodb = boto3.resource("dynamodb", region_name="us-east-1")
-
-    # Create the DynamoDB table.
-    dynamodb.create_table(
-        TableName="users",
-        KeySchema=[
-            {"AttributeName": "forum_name", "KeyType": "HASH"},
-            {"AttributeName": "subject", "KeyType": "RANGE"},
-        ],
-        AttributeDefinitions=[
-            {"AttributeName": "forum_name", "AttributeType": "S"},
-            {"AttributeName": "subject", "AttributeType": "S"},
-        ],
-        ProvisionedThroughput={"ReadCapacityUnits": 5, "WriteCapacityUnits": 5},
-    )
-    table = dynamodb.Table("users")
-
-    table.put_item(
-        Item={"forum_name": "the-key", "subject": "123", "body": "some test message"}
-    )
-    table.put_item(
-        Item={
-            "forum_name": "not-the-key",
-            "subject": "123",
-            "body": "some other test message",
-        }
-    )
-    # Test a scan returning all items
-    results = table.scan(
-        FilterExpression=Key("forum_name").eq("the-key"),
-        ProjectionExpression="body, subject",
-    )["Items"]
-
-    results.should.equal([{"body": "some test message", "subject": "123"}])
-
-    table.put_item(
-        Item={
-            "forum_name": "the-key",
-            "subject": "1234",
-            "body": "yet another test message",
-        }
-    )
-
-    results = table.scan(
-        FilterExpression=Key("forum_name").eq("the-key"), ProjectionExpression="body"
-    )["Items"]
-
-    assert {"body": "some test message"} in results
-    assert {"body": "yet another test message"} in results
-
-    # The projection expression should not remove data from storage
-    results = table.query(KeyConditionExpression=Key("forum_name").eq("the-key"))
-    assert "subject" in results["Items"][0]
-    assert "body" in results["Items"][1]
-    assert "forum_name" in results["Items"][1]
-
-
 @mock_dynamodb2
 def test_nested_projection_expression_using_scan():
     dynamodb = boto3.resource("dynamodb", region_name="us-east-1")
diff --git a/tests/test_dynamodb2/test_dynamodb_table_without_range_key.py b/tests/test_dynamodb2/test_dynamodb_table_without_range_key.py
index b5cc01c84..eaa392df3 100644
--- a/tests/test_dynamodb2/test_dynamodb_table_without_range_key.py
+++ b/tests/test_dynamodb2/test_dynamodb_table_without_range_key.py
@@ -759,18 +759,6 @@ def test_boto3_update_settype_item_with_conditions():
     assert dict(returned_item)["Item"]["foo"].should.equal(set(["baz"]))
 
 
-@mock_dynamodb2
-def test_boto3_put_item_conditions_pass():
-    table = _create_user_table()
-    table.put_item(Item={"username": "johndoe", "foo": "bar"})
-    table.put_item(
-        Item={"username": "johndoe", "foo": "baz"},
-        Expected={"foo": {"ComparisonOperator": "EQ", "AttributeValueList": ["bar"]}},
-    )
-    returned_item = table.get_item(Key={"username": "johndoe"})
-    assert dict(returned_item)["Item"]["foo"].should.equal("baz")
-
-
 @mock_dynamodb2
 def test_scan_pagination():
     table = _create_user_table()
diff --git a/tests/test_ec2/test_amis.py b/tests/test_ec2/test_amis.py
index b2bf4b7f4..a73f7a8ad 100644
--- a/tests/test_ec2/test_amis.py
+++ b/tests/test_ec2/test_amis.py
@@ -783,16 +783,6 @@ def test_ami_registration():
     assert images[0]["State"] == "available", "State should be available."
 
 
-@mock_ec2
-def test_ami_registration():
-    ec2 = boto3.client("ec2", region_name="us-east-1")
-    image_id = ec2.register_image(Name="test-register-image").get("ImageId", "")
-    images = ec2.describe_images(ImageIds=[image_id]).get("Images", [])
-    assert images[0]["Name"] == "test-register-image", "No image was registered."
-    assert images[0]["RootDeviceName"] == "/dev/sda1", "Wrong root device name."
-    assert images[0]["State"] == "available", "State should be available."
-
-
 @mock_ec2
 def test_ami_filter_wildcard():
     ec2_resource = boto3.resource("ec2", region_name="us-west-1")
diff --git a/tests/test_ec2/test_transit_gateway.py b/tests/test_ec2/test_transit_gateway.py
index 7c2141553..cbda02e3d 100644
--- a/tests/test_ec2/test_transit_gateway.py
+++ b/tests/test_ec2/test_transit_gateway.py
@@ -146,7 +146,7 @@ def test_create_transit_gateway_vpn_attachment():
 
 
 @mock_ec2
-def test_create_transit_gateway_vpc_attachment():
+def test_create_and_describe_transit_gateway_vpc_attachment():
     ec2 = boto3.client("ec2", region_name="us-west-1")
     response = ec2.create_transit_gateway_vpc_attachment(
         TransitGatewayId="gateway_id", VpcId="some-vpc-id", SubnetIds=["sub1"]
diff --git a/tests/test_ec2/test_vpn_connections.py b/tests/test_ec2/test_vpn_connections.py
index acb322f8a..985e8fd89 100644
--- a/tests/test_ec2/test_vpn_connections.py
+++ b/tests/test_ec2/test_vpn_connections.py
@@ -77,7 +77,7 @@ def test_create_vpn_connection_with_vpn_gateway():
 
 
 @mock_ec2
-def test_describe_vpn_connections():
+def test_describe_vpn_connections_boto3():
     client = boto3.client("ec2", region_name="us-east-1")
 
     vpn_gateway = client.create_vpn_gateway(Type="ipsec.1").get("VpnGateway", {})
diff --git a/tests/test_elbv2/test_elbv2.py b/tests/test_elbv2/test_elbv2.py
index aec1c090c..7b738dca2 100644
--- a/tests/test_elbv2/test_elbv2.py
+++ b/tests/test_elbv2/test_elbv2.py
@@ -1565,7 +1565,7 @@ def test_set_security_groups():
 
 @mock_elbv2
 @mock_ec2
-def test_set_subnets():
+def test_set_subnets_errors():
     client = boto3.client("elbv2", region_name="us-east-1")
     ec2 = boto3.resource("ec2", region_name="us-east-1")
 
diff --git a/tests/test_iam/test_iam.py b/tests/test_iam/test_iam.py
index 8bb6ef9d8..558472295 100644
--- a/tests/test_iam/test_iam.py
+++ b/tests/test_iam/test_iam.py
@@ -2255,20 +2255,6 @@ def test_update_role_description():
     assert response["Role"]["RoleName"] == "my-role"
 
 
-@mock_iam()
-def test_update_role():
-    conn = boto3.client("iam", region_name="us-east-1")
-
-    with pytest.raises(ClientError):
-        conn.delete_role(RoleName="my-role")
-
-    conn.create_role(
-        RoleName="my-role", AssumeRolePolicyDocument="some policy", Path="/my-path/",
-    )
-    response = conn.update_role_description(RoleName="my-role", Description="test")
-    assert response["Role"]["RoleName"] == "my-role"
-
-
 @mock_iam()
 def test_update_role():
     conn = boto3.client("iam", region_name="us-east-1")
@@ -2779,15 +2765,6 @@ def test_delete_account_password_policy():
     )
 
 
-@mock_iam
-def test_delete_account_password_policy_errors():
-    client = boto3.client("iam", region_name="us-east-1")
-
-    client.delete_account_password_policy.when.called_with().should.throw(
-        ClientError, "The account policy with name PasswordPolicy cannot be found.",
-    )
-
-
 @mock_iam
 def test_get_account_summary():
     client = boto3.client("iam", region_name="us-east-1")
diff --git a/tests/test_iam/test_iam_cloudformation.py b/tests/test_iam/test_iam_cloudformation.py
index f4b2e51ba..6e777dd57 100644
--- a/tests/test_iam/test_iam_cloudformation.py
+++ b/tests/test_iam/test_iam_cloudformation.py
@@ -1009,6 +1009,7 @@ def test_iam_cloudformation_delete_users_access_key():
     user = iam_client.get_user(UserName=user_name)["User"]
     user["UserName"].should.equal(user_name)
     access_keys = iam_client.list_access_keys(UserName=user_name)
+    access_keys["AccessKeyMetadata"][0]["AccessKeyId"].should.equal(access_key_id)
     access_keys["AccessKeyMetadata"][0]["UserName"].should.equal(user_name)
     access_key_id.should.equal(access_keys["AccessKeyMetadata"][0]["AccessKeyId"])
 
diff --git a/tests/test_kms/test_kms.py b/tests/test_kms/test_kms.py
index de7a93fce..ba4ef1707 100644
--- a/tests/test_kms/test_kms.py
+++ b/tests/test_kms/test_kms.py
@@ -311,19 +311,6 @@ def test_put_key_policy_via_alias_should_not_update():
     policy["Policy"].should.equal("my policy")
 
 
-@mock_kms_deprecated
-def test_put_key_policy():
-    conn = boto.kms.connect_to_region("us-west-2")
-
-    key = conn.create_key(
-        policy="my policy", description="my key1", key_usage="ENCRYPT_DECRYPT"
-    )
-    conn.put_key_policy(key["KeyMetadata"]["Arn"], "default", "new policy")
-
-    policy = conn.get_key_policy(key["KeyMetadata"]["KeyId"], "default")
-    policy["Policy"].should.equal("new policy")
-
-
 @mock_kms_deprecated
 def test_list_key_policies():
     conn = boto.kms.connect_to_region("us-west-2")
diff --git a/tests/test_logs/test_integration.py b/tests/test_logs/test_integration.py
index eab839970..590ff29a9 100644
--- a/tests/test_logs/test_integration.py
+++ b/tests/test_logs/test_integration.py
@@ -1,6 +1,7 @@
 import base64
 import boto3
 import json
+import sure  # noqa
 import time
 import zlib
 
@@ -178,7 +179,7 @@ def test_put_subscription_filter_with_lambda():
 
 @mock_lambda
 @mock_logs
-def test_delete_subscription_filter_errors():
+def test_delete_subscription_filter():
     # given
     region_name = "us-east-1"
     client_lambda = boto3.client("lambda", region_name)
diff --git a/tests/test_mediapackage/test_mediapackage.py b/tests/test_mediapackage/test_mediapackage.py
index 579688ced..0c776a9cc 100644
--- a/tests/test_mediapackage/test_mediapackage.py
+++ b/tests/test_mediapackage/test_mediapackage.py
@@ -177,18 +177,6 @@ def test_describe_origin_endpoint_succeeds():
     )
 
 
-def test_describe_unknown_origin_endpoint_throws_error():
-    client = boto3.client("mediapackage", region_name=region)
-    channel_id = "unknown-channel"
-    with pytest.raises(ClientError) as err:
-        client.describe_origin_endpoint(Id=channel_id)
-    err = err.value.response["Error"]
-    err["Code"].should.equal("NotFoundException")
-    err["Message"].should.equal(
-        "originEndpoint with id={} not found".format(str(channel_id))
-    )
-
-
 @mock_mediapackage
 def test_describe_unknown_origin_endpoint_throws_error():
     client = boto3.client("mediapackage", region_name=region)
@@ -219,18 +207,6 @@ def test_delete_origin_endpoint_succeeds():
     )
 
 
-def test_delete_unknown_origin_endpoint_throws_error():
-    client = boto3.client("mediapackage", region_name=region)
-    channel_id = "unknown-channel"
-    with pytest.raises(ClientError) as err:
-        client.delete_origin_endpoint(Id=channel_id)
-    err = err.value.response["Error"]
-    err["Code"].should.equal("NotFoundException")
-    err["Message"].should.equal(
-        "originEndpoint with id={} not found".format(str(channel_id))
-    )
-
-
 @mock_mediapackage
 def test_delete_unknown_origin_endpoint_throws_error():
     client = boto3.client("mediapackage", region_name=region)
@@ -258,22 +234,6 @@ def test_update_origin_endpoint_succeeds():
     update_response["ManifestName"].should.equal("updated-manifest-name")
 
 
-def test_update_unknown_origin_endpoint_throws_error():
-    client = boto3.client("mediapackage", region_name=region)
-    channel_id = "unknown-channel"
-    with pytest.raises(ClientError) as err:
-        client.update_origin_endpoint(
-            Id=channel_id,
-            Description="updated-channel-description",
-            ManifestName="updated-manifest-name",
-        )
-    err = err.value.response["Error"]
-    err["Code"].should.equal("NotFoundException")
-    err["Message"].should.equal(
-        "originEndpoint with id={} not found".format(str(channel_id))
-    )
-
-
 @mock_mediapackage
 def test_update_unknown_origin_endpoint_throws_error():
     client = boto3.client("mediapackage", region_name=region)
diff --git a/tests/test_mediastore/test_mediastore.py b/tests/test_mediastore/test_mediastore.py
index 924406c47..b0dd1851f 100644
--- a/tests/test_mediastore/test_mediastore.py
+++ b/tests/test_mediastore/test_mediastore.py
@@ -221,7 +221,7 @@ def test_list_tags_for_resource_return_none_if_no_tags():
 
 
 @mock_mediastore
-def test_list_tags_for_resource_return_none_if_no_tags():
+def test_list_tags_for_resource_return_error_for_unknown_resource():
     client = boto3.client("mediastore", region_name=region)
     with pytest.raises(ClientError) as ex:
         client.list_tags_for_resource(Resource="not_existing")
diff --git a/tests/test_mediastoredata/test_mediastoredata.py b/tests/test_mediastoredata/test_mediastoredata.py
index 43d3ab3ff..3f1d6d95a 100644
--- a/tests/test_mediastoredata/test_mediastoredata.py
+++ b/tests/test_mediastoredata/test_mediastoredata.py
@@ -70,16 +70,3 @@ def test_list_items():
     len(items).should.equal(1)
     object_exists = any(d["Name"] == object_path for d in items)
     object_exists.should.equal(True)
-
-
-@mock_mediastoredata
-def test_list_items():
-    client = boto3.client("mediastore-data", region_name=region)
-    items = client.list_items()["Items"]
-    len(items).should.equal(0)
-    object_path = "foo"
-    client.put_object(Body="011001", Path=object_path)
-    items = client.list_items()["Items"]
-    len(items).should.equal(1)
-    object_exists = any(d["Name"] == object_path for d in items)
-    object_exists.should.equal(True)
diff --git a/tests/test_organizations/test_organizations_boto3.py b/tests/test_organizations/test_organizations_boto3.py
index 384a86998..ee3a92d0c 100644
--- a/tests/test_organizations/test_organizations_boto3.py
+++ b/tests/test_organizations/test_organizations_boto3.py
@@ -1163,16 +1163,6 @@ def test__get_resource_for_tagging_non_existing_policy():
     ex.message.should.equal("You specified a target that doesn't exist.")
 
 
-def test__get_resource_for_tagging_non_existing_policy():
-    org_backend = OrganizationsBackend()
-    with pytest.raises(TargetNotFoundException) as e:
-        org_backend._get_resource_for_tagging("p-y1vas4da")
-    ex = e.value
-    ex.code.should.equal(400)
-    ex.description.should.contain("TargetNotFoundException")
-    ex.message.should.equal("You specified a target that doesn't exist.")
-
-
 def test__get_resource_to_tag_incorrect_resource():
     org_backend = OrganizationsBackend()
     with pytest.raises(InvalidInputException) as e:
@@ -1323,7 +1313,7 @@ def test_enable_aws_service_access():
     service = response["EnabledServicePrincipals"][0]
     service["ServicePrincipal"].should.equal("config.amazonaws.com")
     date_enabled = service["DateEnabled"]
-    date_enabled["DateEnabled"].should.be.a(datetime)
+    date_enabled.should.be.a(datetime)
 
     # enabling the same service again should not result in any error or change
     # when
@@ -1338,7 +1328,7 @@ def test_enable_aws_service_access():
 
 
 @mock_organizations
-def test_enable_aws_service_access():
+def test_enable_aws_service_access_error():
     client = boto3.client("organizations", region_name="us-east-1")
     client.create_organization(FeatureSet="ALL")
 
@@ -1354,7 +1344,7 @@ def test_enable_aws_service_access():
 
 
 @mock_organizations
-def test_enable_aws_service_access():
+def test_enable_multiple_aws_service_access():
     # given
     client = boto3.client("organizations", region_name="us-east-1")
     client.create_organization(FeatureSet="ALL")
diff --git a/tests/test_redshift/test_redshift.py b/tests/test_redshift/test_redshift.py
index dfb3186aa..472f3c5ec 100644
--- a/tests/test_redshift/test_redshift.py
+++ b/tests/test_redshift/test_redshift.py
@@ -1569,17 +1569,7 @@ def test_resize_cluster():
 
 
 @mock_redshift
-def test_get_cluster_credentials_non_existent_cluster():
-    client = boto3.client("redshift", region_name="us-east-1")
-
-    with pytest.raises(ClientError) as ex:
-        client.get_cluster_credentials(ClusterIdentifier="non-existent")
-    ex.value.response["Error"]["Code"].should.equal("ClusterNotFound")
-    ex.value.response["Error"]["Message"].should.match(r"Cluster .+ not found.")
-
-
-@mock_redshift
-def test_get_cluster_credentials_non_existent_cluster():
+def test_get_cluster_credentials_non_existent_cluster_and_user():
     client = boto3.client("redshift", region_name="us-east-1")
 
     with pytest.raises(ClientError) as ex:
diff --git a/tests/test_sqs/test_sqs.py b/tests/test_sqs/test_sqs.py
index 2efc0ae7c..261078c60 100644
--- a/tests/test_sqs/test_sqs.py
+++ b/tests/test_sqs/test_sqs.py
@@ -2813,7 +2813,7 @@ def test_fifo_send_message_when_same_group_id_is_in_dlq():
 
 
 @mock_sqs
-def test_message_attributes_in_receive_message():
+def test_message_attributes_contains_trace_header():
     sqs = boto3.resource("sqs", region_name="us-east-1")
     conn = boto3.client("sqs", region_name="us-east-1")
     conn.create_queue(QueueName="test-queue")
diff --git a/tests/test_sts/test_sts.py b/tests/test_sts/test_sts.py
index 6505ab206..3fa656a01 100644
--- a/tests/test_sts/test_sts.py
+++ b/tests/test_sts/test_sts.py
@@ -748,61 +748,3 @@ def test_sts_regions(region):
     client = boto3.client("sts", region_name=region)
     resp = client.get_caller_identity()
     resp["ResponseMetadata"]["HTTPStatusCode"].should.equal(200)
-
-
-@mock_sts
-@mock_iam
-def test_get_caller_identity_with_iam_user_credentials():
-    iam_client = boto3.client("iam", region_name="us-east-1")
-    iam_user_name = "new-user"
-    iam_user = iam_client.create_user(UserName=iam_user_name)["User"]
-    access_key = iam_client.create_access_key(UserName=iam_user_name)["AccessKey"]
-
-    identity = boto3.client(
-        "sts",
-        region_name="us-east-1",
-        aws_access_key_id=access_key["AccessKeyId"],
-        aws_secret_access_key=access_key["SecretAccessKey"],
-    ).get_caller_identity()
-
-    identity["Arn"].should.equal(iam_user["Arn"])
-    identity["UserId"].should.equal(iam_user["UserId"])
-    identity["Account"].should.equal(str(ACCOUNT_ID))
-
-
-@mock_sts
-@mock_iam
-def test_get_caller_identity_with_assumed_role_credentials():
-    iam_client = boto3.client("iam", region_name="us-east-1")
-    sts_client = boto3.client("sts", region_name="us-east-1")
-    iam_role_name = "new-user"
-    trust_policy_document = {
-        "Version": "2012-10-17",
-        "Statement": {
-            "Effect": "Allow",
-            "Principal": {
-                "AWS": "arn:aws:iam::{account_id}:root".format(account_id=ACCOUNT_ID)
-            },
-            "Action": "sts:AssumeRole",
-        },
-    }
-    iam_role_arn = iam_client.role_arn = iam_client.create_role(
-        RoleName=iam_role_name,
-        AssumeRolePolicyDocument=json.dumps(trust_policy_document),
-    )["Role"]["Arn"]
-    session_name = "new-session"
-    assumed_role = sts_client.assume_role(
-        RoleArn=iam_role_arn, RoleSessionName=session_name
-    )
-    access_key = assumed_role["Credentials"]
-
-    identity = boto3.client(
-        "sts",
-        region_name="us-east-1",
-        aws_access_key_id=access_key["AccessKeyId"],
-        aws_secret_access_key=access_key["SecretAccessKey"],
-    ).get_caller_identity()
-
-    identity["Arn"].should.equal(assumed_role["AssumedRoleUser"]["Arn"])
-    identity["UserId"].should.equal(assumed_role["AssumedRoleUser"]["AssumedRoleId"])
-    identity["Account"].should.equal(str(ACCOUNT_ID))