title: Pushing .gitignore files to specific remote
body: <p>I made a Sinatra app, that will be hosted on Heroku, and the source will be up on GitHub. The problem is that i have a file with API keys, that is currently in .gitignore. Is there a way, that I can push my repo to heroku with the key file and exclude the file when pushing to GitHub?</p>
  
  <p>Thanks in advance!</p>