Ensure newly created NAT gateways get converted to snake dict
Remove custom code, and associated test, for generating snake
dict and use `camel_dict_to_snake_dict`
Make use of `required_if` rather than bespoke parameter checks
Remove ec2_vpc_nat_gateway from pep8 legacy files list
* [cloud][tests] Create fixtures for using placebo to test boto3-using modules
* Use pytest's importorskip instead of manually skipping on missing deps
* Fix imports in cloudformation module
* Delete unused code
* Add maybe_sleep fixtures to speed up recorded test runs
* Build basic placebo-CFN tests
* Commit placebo recordings of basic stack operations
* Add placebo to test-requires
* Allow unit tests to run regardless of environment by setting a default region
* Use explicit relative import for Python 3 compat
* Use __name__ attribute that works on Python 2 and 3
* lambda module - some tests; demonstrates no update when only one parameter changed fixed in 22701806.
* lambda module - tests - code clean up
* lambda module - tests - fix update usage assertions
* lambda module - rework mocking in region warning test
