title: Set Env variables based on grunt task
body: <p>I have a webapp (emberjs) that I need to set env variables based on grunt task. So when I run <code>grunt server</code> it would choose <code>development</code>, and url will be set to <code>localhost:5000</code>. But when i do <code>grunt build</code>, it would choose <code>production</code> and url will be set to <code>production.com</code>. </p>
  
  <p>The main issue for me is, how to read those variables from ember. Or how to make grunt look for a variable and change it based on the task</p>
  
  <p>Is it possible to do something like that?</p>