* Split out cache plugin unit tests.
* Rename unit tests to match code under test.
* Relocate unit test code to match code under test.
* Another rename.
* Update sanity ignores.
* Simplify permission changing code for rabbitmq_user module
* Add check for multiple permission dicts for same host to rabbitmq_user module
* Add docstring for _get_permission method of rabbitmq_user
* Fix method that compares vhost permissions in rabbitmq_user
* Add tests for rabbitmq_user module
* Add helper function for simulating collections.Counter functionality