Fix migration testcase 1-to-1 between stack and raw_template
Fix migration testcase 1-to-1 between stack and raw_template

_pre_upgrade_047 unit test case creates multiple stacks with same
raw_template id, which is invalid. This patch fixes this issue

Change-Id: Ibcaa8bbaa71fb2880c50cc0d634c6fcf6e12a80f
Closes-bug: #1429029

gonzolino/heat,pratikmallya/heat,dragorosson/heat,pshchelo/heat,maestro-hybrid-cloud/heat,noironetworks/heat,cwolferh/heat-scratch,cryptickp/heat,openstack/heat,dragorosson/heat,rh-s/heat,rdo-management/heat,gonzolino/heat,steveb/heat,rh-s/heat,dims/heat,pshchelo/heat,openstack/heat,jasondunsmore/heat,dims/heat,takeshineshiro/heat,noironetworks/heat,maestro-hybrid-cloud/heat,cwolferh/heat-scratch,jasondunsmore/heat,srznew/heat,miguelgrinberg/heat,cryptickp/heat,srznew/heat,rdo-management/heat,steveb/heat,takeshineshiro/heat,miguelgrinberg/heat,pratikmallya/heat