Replace assertEqual(None, *) with assertIsNone in tests
Replace assertEqual(None, *) with assertIsNone in tests

Replace assertEqual(None, *) with assertIsNone in tests to have
more clear messages in case of failure.

Change-Id: Id1cc5e677a8df90afd07ed51c4845e90dfee0cc3
Closes-Bug: #1280522

openstack/searchlight,openstack/searchlight,openstack/searchlight