Fix using mock return_value in unittests
Fix using mock return_value in unittests

Change-Id: If2eef9df7e708e0cf382de071b4db58baebea9a7

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