Mock delete_network in Quantum unit tests
Mock delete_network in Quantum unit tests

Change-Id: I0a1f0e56ed84aa4efcdf7c65c7c634f738bdddda

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