Add secure-rbac test for Containers

This patch adds rbac tests to the Containers resource to test
secure-rbac policies within a project

This patch also removes the use of do_request in the existing tests
as that method is being deprecated in favor of using the clients
directly.

* PEP8 Fixes
* Fix the plurality of the method names
* Remove _by_id from certain methods to maintain consistency

Change-Id: I80aba2934110965866d1583309df7f2ca9ef4c27
2 files changed