title: How to overcome 'Coudn't find that formation' error when adding web dynos to Heroku django app?
body: <p>I'm trying to get deploy a simple django app, and have successfully pushed my git repository to Heroku. However, when I attempt to run:</p>
  
  <pre><code>heroku ps:scale web=1
  </code></pre>
  
  <p>I get the following error</p>
  
  <pre><code>Scaling dynos... failed
   !    Couldn't find that formation.
  </code></pre>
  
  <p>Any thoughts as to what the problem might be? The contents of the Procfile  (below) are correct to the best of my knowledge.</p>
  
  <pre><code>web: gunicorn my_app_name.wsgi
  </code></pre>