Tenants API Role Tests Parity

1. Added an admin package to Identity for tests parity.
2. Added a role test to admin package.
3. Refactored fixtures as per role test parity requirements.
4. Completed testing role creation functionality.
5. Completed testing role deletion functionality.
6. Added assign role to a tenant user test.
7. Completed testing role functionality on tenants-api client.
8. Fixed reviewer comments - refactored indentity fixtures and test_roles.
9. Fixed reviewer comments - better way of cleaning up test data.
10. Refactored fixtures.
11. Changed import of rand_name.
12. Renamed test_repo to cloudroast.
13. Fixed reviwer comment - refectored fixtures.
14. Refactored test_roles.
15. Fixed reviewer comment - flipped up order in assertEqual.

Change-Id: I5ceb4563373c0864703b0053e3673c865f32b0e5
Merge "Tenants API Role Tests Parity"