Add test for grant CRUD on test_backend

[Samuel de Medeiros Queiroz]

The fact of not having tests for this may cause some bugs.
For example, in KVS backend we call a non existent method and it would be avoided if we had such tests. [1]

[1] https://github.com/openstack/keystone/blame/master/keystone/assignment/backends/kvs.py#L512

[Lance Bragstad (lbragstad)]

Samuel, if you wanted the test to be kvs specific, you could consider adding it here:

https://github.com/openstack/keystone/blob/master/keystone/tests/test_backend_kvs.py

[Samuel de Medeiros Queiroz (samueldmq)]

Lance, actually I really would like to add on test_backend so every backend would be tested, not only KVS.

[Lance Bragstad (lbragstad)]

Samuel,

Correct, in that case you could add it to test_backend.py

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/123590

[OpenStack Infra (hudson-openstack)]

Change abandoned by Samuel de Medeiros Queiroz (<email address hidden>) on branch: master
Review: https://review.openstack.org/123590

[Steve Martinelli (stevemar)]

i think the testing here is sufficient https://github.com/openstack/keystone/blob/5de11025f45ca10d2b02b70234c1305fae91766c/keystone/tests/unit/test_backend.py#L1101-L1148 and covers a lot of what was in the abandoned patch