Pin SQLAlchemy to 0.7.x
Pin SQLAlchemy to 0.7.x

0.7.10 has been released and is compatible with 0.7.x. Instead
of pinning to 0.7.9, simply pin to 0.7.x to avoid SQLAlchemy 0.8

Fixes: Bug #1153983

Change-Id: I1a2ea0c36161df15fd55e95a6679628d14858944

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