heat engine : remove unused EC2 style auth from engine
heat engine : remove unused EC2 style auth from engine

We handle EC2 style auth at the heat-api-cfn level, so EC2
style authenticated requests simply pass us an auth_token in
the context, so remove this duplicate/dead code.

Ref #268

Change-Id: I17708cb6ef4b0eb4989d47c116b6211f0d419dcb
Signed-off-by: Steven Hardy <4d1810d1ff6d7f22d774341c4549c02173d2f2ab@redhat.com>

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