This test is flaky, but when it fails we don't get any indication as to why.
This commit ensures that the reason for failure will be part of the assertion
message.
Once we have information about why this test fails, we can troubleshoot further
and hopefully come up with a permanent fix.
* Add get_function_configuration support for Lambda
* remove unnesecary code from test and use _lambda_region when asserting
* rename function and skip coping configuration
* run black formatting
* lambda-responses: add method to dispatch concurrency calls
* lambda-resources: add route to handle concurrency requests
* lambda-model: implement put_function_concurrency and concurrency attribute
* put-concurrency-tests: add one simple test
* get_function: add concurrency entry - with test
* lambda-reserved-concurrency: cloudformation support
* lambda-concurrency: implement delete_reserved with tests
* lambda-concurrency: implement get_reserved with tests
* lint
* implementation-cov: mark delete_function_concurrency, put_function_concurrency and get_function_concurrency
* botocore doesn't display concurrency entry for lambdas without it
* lambda(refactor): improvements on response's handler
* change line position for uuid and last_modified because they're not input parameters
* add event_source_arn validator and setter
* refactor batch_size as setter
* add helper function to parse arn and return source service
* fix for EventSource's create_from_cfn, there was no reference in the lambda object for the esm if created by cfn
* add esm deletion by cloudformation
* remove unused variable in test
* add cfn's update
* add complete implementation of delete_from_cfn
* blacked changed files
* fix test with invalid batchsize for sqs
* Dynamodb2 Table - Bugfix for localindex and implemented get_cfn_attributes
* Dynamodb2 eventsource - fix test to use StreamArn attribute
* Lambda Test - fix test_update_event_source_mapping
According to the AWS documentation:
```
The HTTP status code will be in the 200 range for successful request.
For the RequestResponse invocation type this status code will be 200.
For the Event invocation type this status code will be 202.
For the DryRun invocation type the status code will be 204.
```
