title: How can I run script after deploy to heroku
body: <p>I have an application in node.js which depends on env variables. I made some changes in code and now one of this vars should be changed after deploy. I don't want to do this manually. What is the best practise to do this automatically. </p>
  
  <p>I guess that running some script after deploy could be solution, but I want to run this script only once (with this one particular change).</p>
  
  <p>My only idea is that I should have script that will be checking (after each deploy) some directory if there is another script to run and then run it and remove it. But how can I achieve that?</p>