Updated openstack/openstack
Project: openstack/heat  ab1f21ae3ff42f37c1f6bc5d9c0311b44062bb8e
null
Modify assert statement when comparing with None

Replace assertEqual(None, *) with assertIsNone in heat's
tests to have more clear messages in case of failure.
Also, replace assertNotEqual(None, *) with assertIsNotNone
for the same reason.

Change-Id: I34dbf9b87c7c8c6ca4949b53bd5ef763a9c2fc24
Closes-Bug: #1280522