title: saving a folder from being destroyed after push on heroku
body: <p>I have an app that lets users upload documents. The app saves the documents to a folder on the server, say users_documents. The app is hosted on Heroku.</p>
  
  <p>When I do a git push heroku master the new app is deployed but all the files in users_documents are deleted, is there a way to tell git (or heroku) not to rewrite that folder?</p>