* Add support for empty strings in non-key attributes
https://github.com/spulec/moto/issues/3339
* Nose, not pytest
* Revert "Nose, not pytest"
This reverts commit 5a3cf6c887dd9fafa49096c82cfa3a3b7f91d224.
* PUT is default action
Part of structured approach for UpdateExpressions:
1) Expression gets parsed into a tokenlist (tokenized)
2) Tokenlist get transformed to expression tree (AST)
3) The AST gets validated (full semantic correctness)
4) AST gets processed to perform the update -> this commit
This commit uses the AST to execute the UpdateExpression.
All the existing tests pass. The only tests that have been
updated are in test_dynamodb_table_with_range_key.py because
they wrongly allow adding a set to a path that doesn't exist.
This has been alligend to correspond to the behavior of AWS
DynamoDB.
This commit will resolve https://github.com/spulec/moto/issues/2806
Multiple tests have been implemented that verify this.
