We assume you have an account on heroku, the heroku toolbet installed and logged in.
At the root directory of your repo:
heroku create APPNAME --buildpack https://github.com/stephanmelzer/heroku-buildpack-nodejs-grunt-compass.git
where APPNAME is the name you want to give your app.
To deploy your master branch :
git push heroku master
To deploy the branch YOURBRANCH :
git push heroku YOURBRANCH:master