Set the remote on app creation to an HTTP remote, instead of an SSH remote.
The HTTP remote is very much a work in progress. It's location and functionality will change.
$ heroku plugins:install https://github.com/nzoschke/heroku-httpgit.git
$ heroku create -s cedar
Creating stark-sunrise-7399... done, stack is cedar
http://stark-sunrise-7399.herokuapp.com/ | git@heroku.com:stark-sunrise-7399.git
Git remote heroku added
$ git remote -v
heroku http://code-production.herokuapp.com/stark-sunrise-7399.git (fetch)
heroku http://code-production.herokuapp.com/stark-sunrise-7399.git (push)
$ git push heroku master
Counting objects: 1919, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (665/665), done.
Writing objects: 100% (1919/1919), 25.37 MiB | 1.54 MiB/s, done.
Total 1919 (delta 1160), reused 1919 (delta 1160)
remote:
remote: -----> Heroku receiving push
...