DATABASE_URL config var now set automatically when provisioning Postgres add-on

Change effective on 20 March 2014

As of now, if a Postgres add-on is provisioned to an app that does not have a DATABASE_URL config key, DATABASE_URL will be automatically set to the URL of the provisioned database in addition to adding the HEROKU_POSTGRESQL_COLOR_URL config.

$ heroku addons:add heroku-postgresql
...

$ heroku config
=== example-app Config Vars
DATABASE_URL:               postgres://{user}:{password}@{hostname}:{port}/{database-name}
HEROKU_POSTGRESQL_AQUA_URL: postgres://{user}:{password}@{hostname}:{port}/{database-name}