Use a default SLUG_ID value
otherwise the build fails using the Heroku beta [builds api](https://gist.github.com/friism/c5df3e3e0091bbc6b9f2)
Please register or sign in to comment
otherwise the build fails using the Heroku beta [builds api](https://gist.github.com/friism/c5df3e3e0091bbc6b9f2)