Steps to reset database in Heroku:
1. Drop the database, when SHARED_DATABASE_URL is used:
heroku pg:reset DATABASE
2. Recreate the database with nothing in it:
heroku run rake db:migrate
3. Populate the database with your seed data:
heroku run rake db:seed
Steps 2 and 3 can be combined into one command by executing this:
heroku run rake db:setup