update to reflect heroku's db changes
update to reflect heroku's db changes

Heroku has phased out `shared-database` in favor of `heroku-postgresql:dev` & `heroku-postgresql:basic` -- see this article for more information. https://devcenter.heroku.com/articles/migrating-from-shared-database-to-heroku-postgres
ngoldman/martin,ngoldman/martin,ngoldman/martin