title: Update to a specific version of PHPUnit
body: <p>Currently my system installed phpunit is on 4.3.1</p>
  
  <p>Doing phpunit --self-update will update to the latest version of phpunit which is 5.3.* at the moment.</p>
  
  <p>I like to update it to a specific version (4.8.24)</p>
  
  <p>How am I suppose to do this?</p>
  
  <p>Note: I know about the composer option, but I would like to do it on my system installed phpunit.</p>