Unlike Cinder, Nova etc., we haven't had any sqlalchemy-migrate-based
migrations in Heat for some time. That means we don't need a transition
period to handle users that may not have the latest
sqlalchemy-migrate-based migration and we can remove these migrations
immediately. Doing so also means we can also remove sqlalchemy-migrate
from our dependencies. Hurrah!
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>
Change-Id: I825c58a42e9d430c9d660dae9bb70d1cb6f91079