New test cases for "zone recordsets" test suite

1) "test_show_recordsets_impersonate_another_project"
   As Admin tenant show recordset for another tenant
   using "x-auth-sudo-project-id" HTTP header.

2) "test_admin_list_all_recordsets_for_a_project"
   As Admin tenant list all recordsets for another tenant
   using "x-auth-all-projects" HTTP header.

3) "test_create_recordset_for_other_tenant"
   Try to create a recordset as Alt tenant, using a zone
   that is owned by Primary tenant.

4) "test_show_recordsets_invalid_ids"
   Use invalid "zone_id" or invalid "recordset_id" to show
   a recordset. Expected: 404 NotFound

Change-Id: Ieb3f19a95718baa7bcf0aaacacc424886e6feaba
2 files changed