Merge "Utilizes assertIsNone and assertIsNotNone"

diff --cc neutron/tests/unit/linuxbridge/test_lb_neutron_agent.py
Simple merge

diff --cc neutron/tests/unit/linuxbridge/test_lb_security_group.py
Simple merge

diff --cc neutron/tests/unit/mlnx/test_mlnx_security_group.py
Simple merge

diff --cc neutron/tests/unit/nicira/test_nicira_plugin.py
Simple merge

diff --cc neutron/tests/unit/openvswitch/test_ovs_security_group.py
Simple merge

diff --cc neutron/tests/unit/ryu/test_ryu_security_group.py
Simple merge