Add unit tests for EngineManager create/update/delete_stack
Add unit tests for EngineManager create/update/delete_stack

Change-Id: I25aeb43ea3f5a9426b8f742a605b9699dc2b9851
Signed-off-by: Zane Bitter <1899fff8e7db19a598ee9d835aa1a232f82ea264@redhat.com>

varunarya10/heat,pratikmallya/heat,rdo-management/heat,dims/heat,cryptickp/heat,jasondunsmore/heat,JioCloud/heat,redhat-openstack/heat,Triv90/Heat,miguelgrinberg/heat,cryptickp/heat,citrix-openstack-build/heat,noironetworks/heat,gonzolino/heat,jasondunsmore/heat,NeCTAR-RC/heat,pshchelo/heat,dragorosson/heat,dims/heat,rickerc/heat_audit,srznew/heat,rickerc/heat_audit,NeCTAR-RC/heat,srznew/heat,ntt-sic/heat,openstack/heat,maestro-hybrid-cloud/heat,takeshineshiro/heat,JioCloud/heat,noironetworks/heat,redhat-openstack/heat,pratikmallya/heat,citrix-openstack-build/heat,miguelgrinberg/heat,rdo-management/heat,varunarya10/heat,Triv90/Heat,pshchelo/heat,cwolferh/heat-scratch,dragorosson/heat,ntt-sic/heat,rh-s/heat,steveb/heat,maestro-hybrid-cloud/heat,Triv90/Heat,rh-s/heat,steveb/heat,takeshineshiro/heat,openstack/heat,cwolferh/heat-scratch,gonzolino/heat