We at @icalialabs works with Rails apps all the time, and we make changes daily, so it is fair to say we need sometimes to restart the apps databases. By the way we deploy to Heroku, great service to get you up and running in no time.
It is really easy to reset your postgres database on Heroku just by running:
$ heroku pg:reset DATABASE
To run the migrations and seed for your database, run:
$ heroku run rake db:setup
Or if you feel like want to do it individually:
$ heroku run rake db:migrate
$ heroku run rake db:seed