title: Updating my app with git and Heroku delete pictures
body: <p>I'm facing a problem that I don't know how to solve.
  Basically, when my app is running live on Heroku, I can upload pictures in the platform: those pictures are saved in a directory of my Angular app : <code>/public/images</code>.</p>
  
  <p>But then, everytime I update my app like this:</p>
  
  <pre><code>git add .
  git commit -m 'my message'
  git push heroku master
  </code></pre>
  
  <p>My pictures in <code>/public/images</code> just disappears.</p>
  
  <p>Do you know how I could update my app without deleting the pictures?
  I also tried to pull before, but it tells me that everything is up to date.</p>
  
  <p>PS: To be more specific, it's when I use <code>git push heroku master</code> to deploy my app that my file <code>/public/images</code> is removed and replaced.</p>