Tenants API Behaviors:

1. Added tenants-api behaviors.
2. Refactored methods as per Role Tests Parity requirements.
3. Fixed serialization/deserialization issues to use reponse entity.
4. Renamed TenantClientBehavior to TenantsBehaviors
5. Raised exceptions when two or more users (roles or tenants) have the same name.

Change-Id: I00ad1cf7948ec626737a128871532464b86372ad
Merge "Tenants API Behaviors:"