Use heat-manage to sync heat db.

heat-db-setup has been deprecated and doesn't work when
devstack uses postgres and mysql isn't installed.

This is causing postgres gating to fail for heat.

Change-Id: I84f0a2d40f0033e52c87b6f0c9c7265471134ffe
Merge "Use heat-manage to sync heat db."
Merge branch 'master' of github.com:openstack-dev/devstack