title: Config variables not visible as environment variables in Heroku app
body: <p>I've set a few custom config variables. I can see them in my application's settings->config variables. I can also see the values with the heroku config command. But when I start my application the environment variables are not there. I use (System/getenv "MY_VARIABLE_NAME") in Clojure to fetch them. </p>
  
  <p>Is it because I try to retrieve them at boot time? Are they only available later? Or is there some twitch which I can get rid of by doing some trick? I've used config variables in Heroku before and they've worked, I don't know what's the problem here...</p>