title: failing to enable user-env-compile on Heroku
body: <p>it is the first time I ask for something so sorry if I'm not enough precise!</p>
  
  <p>I tried to upload my rails app on heroku using enabling the user-env-compile to manage my secret keys but I have an error "No such feature: user-env-compile".</p>
  
  <p>I checked on Heroku devcenter and seems that user-env-compile has been deprecated and replaced by the ENV_DIR argument.</p>
  
  <p>Here the link: 
  <a href="https://devcenter.heroku.com/articles/labs-user-env-compile">https://devcenter.heroku.com/articles/labs-user-env-compile</a></p>
  
  <p>I cant really get what to do! can someone explain better to me what I'm supposed to do?</p>
  
  <p>thank you,</p>
  
  <p>Federico</p>