Using assertIsNone() instead of assertEqual(None, ...)
Using assertIsNone() instead of assertEqual(None, ...)

Following OpenStack Style Guidelines[1]:
[H203] Unit test assertions tend to give better messages for more
specific assertions. As a result, assertIsNone(...) is preferred
over assertEqual(None, ...) and assertIs(None, ...)

[1] http://docs.openstack.org/developer/hacking/#unit-tests-and-assertraises

Change-Id: I165921ca1053041104c915bf0d3f567e6f5c09eb

szaher/freezer-api,openstack/freezer-api,openstack/freezer-api,openstack/freezer-api,szaher/freezer-api,szaher/freezer-api,szaher/freezer-api,openstack/freezer-api