Heroku deploy with ruby

I'm moving my first steps with ruby rails. Actually i'm tring to send an email for activate the account and searching in internet i've found heroku service. Now, after reading some guides, including the official one, i'v tried to deploy my app using ruby and and nodejs buildpacks and still got this error:

   ----> Failed to detect app matching no buildpack
   More info: https://devcenter.heroku.com/articles/buildpacks#detection-failure
   !     Push failed

Now i'v tried adding ruby version in my gem files and still don't work.

This is my repo https://github.com/Klunkh/CarAdvisor

Any suggestion would be appreciated. Thanks!

via Matteo Haykel Monteverde