This is significantly easier than Cinder, Nova etc. as Heat hasn't had
any database migrations in multiple cycles, meaning we don't need to
worry about having to apply any older sqlalchemy-migrate migrations
before switching to alembic. Instead, we simply need to determine we're
upgrading a deployment that was previously using sqlalchemy-migrate,
upgrading a deployment that has already migrated to alembic, or
deploying a new deployment, adjusting accordingly.
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>
Change-Id: I808af9cb21ba21808209b1daddac7426f4cad310
64621053c2