This is better than nothing but if you have to run migrations before your database is usable, you want an approach like the one I use in pgtestdb — use one server for all your tests, but give them each different databases by cloning from one that's already set up with all the schemas correctly migrated.
I did something similar with pg_tmp as well. I also had a lot of tests around migrations, so there was a lot of tests that would 1) ask for a DB of version x 2) insert things into the DB, etc 3) migrate to version y 4) ensure the DB is appropriate (note: this was not a SaaS).
