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

From python 2.7 onwards, some new method such as assertIsNone
equivalent to the assertEqual,this will simplify the number of
parameters.see [1] for more informaton.
[1]:https://docs.python.org/2.7/library/unittest.html#unittest.TestCase.assertIsNone

Change-Id: I2a42228cff4cdcf92c87ae0800782cbd641ff665

noironetworks/neutron,sebrandon1/neutron,huntxu/neutron,openstack/neutron,eayunstack/neutron,openstack/neutron,huntxu/neutron,cloudbase/neutron,igor-toga/local-snat,noironetworks/neutron,eayunstack/neutron,cloudbase/neutron,sebrandon1/neutron,openstack/neutron,mahak/neutron,mahak/neutron,igor-toga/local-snat,mahak/neutron