heat engine : workaround lack of no_cache on essex
heat engine : workaround lack of no_cache on essex

no_cache novaclient fix doesn't work on essex, so try
both the essex and the folsom compatible novaclient
prototypes

Change-Id: I0749f821981550d7a5f5a95e2f5951c77d8e1529
Signed-off-by: Steven Hardy <4d1810d1ff6d7f22d774341c4549c02173d2f2ab@redhat.com>

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