title: Can you arc diff with group as reviewer?
body: <p>we are a lot of people at work and sometimes I just don't remember the user names of all of them, we are all in the same group and I would like to know if it's possible to run something like:</p>
  
  <p><code>arc diff --reviewers Developers</code></p>
  
  <p>Assuming that Developers is a group that holds all the users that are developers.</p>
  
  <p>I tried this command with no success, is there any other flag that can achieve this?</p>
  
  <p>Thank you very much.</p>