Updated openstack/openstack
Project: openstack/nova  93b6883d33245783bda3a4ccd22a71412c5cb9ad
null
Utilizes assertIsNone and assertIsNotNone - tests/virt

Using assertTrue and the 'is None' operator to test if an element is None
is too python2.4. Our unit testing framework 'testtools' supports
assertIsNone and assertIsNotNone, included from python 2.7,
which were created for these types of tests.

Change-Id: Iee1379b941f93388900e89388676000b845fc8fc