Convert from mox to mock in test_signal
Convert from mox to mock in test_signal

Change-Id: I7988c9e614aabaec2aa18fe5a282b02e6a70d289
Implements: blueprint mox-to-mock-conversion

jasondunsmore/heat,dims/heat,jasondunsmore/heat,steveb/heat,noironetworks/heat,steveb/heat,cwolferh/heat-scratch,cwolferh/heat-scratch,dims/heat,noironetworks/heat,openstack/heat,openstack/heat