title: Heroku - How can I undo a push on heroku?
body: <p>After pushing my app on heroku, my app crashes.
  I don't want to make a git rebase before getting heroku last version (if I do so, I'll get fast-forward errors...)</p>
  
  <p>I would be pleased to know if there is a command to do it (I don't find it on the heroku doc)</p>
  
  <p>Thank you!</p>