Adding new test cases to: "Zone Ownership Transfers" test suite.

1) test_show_transfer_request_impersonate_another_project
   Test is based on: "x-auth-sudo-project-id" HTTP header
2) test_list_transfer_requests_all_projects
   Test is based on: "x-auth-all-projects" HTTP header
3) test_zone_transfer_target_project
   Test validates that only targeted project is able to
   accept the transfer request.
4) Improving the existing scenario test: "test_zone_transfer"
   Zone ownership transfer shouldn't work more than once.

Change-Id: I1b345de2c9756ba1bcb0ec7b361c90baff3acb60
3 files changed