title: Force protractor's onPrepare to wait for async http request
body: <p>My protractor conf.js,<code>onPrepare</code> function needs to make a http request that looks like,</p>
  
  <pre><code>onPrepare: function(done) {
      request.get('http://pepper/sysid')
        .end(function(err, resp){
          if(err || !resp.ok){
            log("there is an error " + err.message)
            done()
          }else{
            global.sysid = resp.sysid
            done()
           }
        })
  </code></pre>
  
  <p>It throws error as,<code>done is not a function</code></p>
  
  <p>Is there any other way, that i can force the callback inside <code>onPrepare</code> to be invoked before my tests start execution?</p>