title: rails db:migrate fails rake aborted ActiveRecord::NoDatabaseError
body: <p>On cloud9 IDE I installed postgresql because that is needed to deploy on Heroku, I am learning this so I am not sure, when I try to migrate a simple database table   I used this
  bundle exec rake db:migrate and I get a rake aborted and a ActiveRecord::NoDatabaseError:  FATAL: role "ubuntu" does not exist.</p>