add the postgres addon if no DATABASE_URL is known.

bin/setup_heroku

@@ -81,10 +81,16 @@ unless $config['DOMAIN']
   first_time = true
 end
 
-set_value 'BUILDPACK_URL', "https://github.com/ddollar/heroku-buildpack-multi.git"
+set_value 'BUILDPACK_URL', "https://github.com/heroku/heroku-buildpack-multi.git"
 set_value 'PROCFILE_PATH', "deployment/heroku/Procfile.heroku", force: false
 set_value 'ON_HEROKU', "true"
 
+unless $config['DATABASE_URL']
+  puts "Setting up the postgres addon"
+  puts capture("heroku addons:add heroku-postgresql")
+  puts
+end
+
 unless $config['SMTP_DOMAIN'] && $config['SMTP_USER_NAME'] && $config['SMTP_PASSWORD'] && $config['SMTP_SERVER'] && $config['EMAIL_FROM_ADDRESS']
   puts "Okay, let's setup outgoing email settings.  The simplest solution is to use the free sendgrid Heroku addon."
   puts "If you'd like to use your own server, or your Gmail account, please see .env.example and set"