github commits.coffee with Hubot on Heroku

If your Hubot is on Heroku and you want to use Github webhooks with github-commits.coffee

1. You need to modify the Procfile to a web process to allow web requests to get Hubot.
2. Commit: git commit -am "update Procfile"
3. And push your code: git push heroku master
4. Scale Heroku: heroku ps:scale web=1

Has explained on Heroku Procfile documentation:

The `web` process type is special as it’s the only process type that will receive HTTP traffic from Heroku’s routers. Other process types can be named arbitrarily.

In your repository: https://github.com/_username_/_repo_/settings/hooks > WebHook URLs http://app_name.herokuapp.com/hubot/gh-commits?room=1