Adding more tests to "Designate Limits" tests suite

1) test_list_designate_limits_as_primary_user
   Make sure that the expected limit fields are listed
   in Designate Limits API response
   Note: this test replaces "test_list_designate_limits"
   that was using Admin user.

2) test_list_designate_impersonate_another_user_as_admin
   Make sure that the Limit values retrieved for a Primary
   user are the same for Admin user when "x-auth-sudo-project-id"
   is included in API request sent by Admin.

3) test_list_designate_impersonate_another_user_as_alt
   Make sure that the Alt user is not able to impersonate
   Primary user and that API responds with "403 Forbidden"
   Note: such an option is available for Admin user only.

4) test_list_designate_limits_all_projects
   Make sure that the list of retrieved Designate Limits for
   all projects, contains both project IDs used within the
   test setup: Primary and Alt.

Change-Id: Icd9c17110375c5055778d22a6d7c23529bd3649b
1 file changed