option hitCallback doesn't work for google analytics.

[devinrhode2]

I'm trying to track outbound link navigations, and found that the way to do this with google analytics is to send an event and in the options set a hitCallback key to a function that will be called when the event has been received. This just flat out doesn't seem to work.. here's my component.js:

function exitToMessenger() {
  console.log('redirecting to messenger.com!!')
  window.location.href = 'https://www.messenger.com/t/heyimlea';
}

export default Ember.Component.extend({
  metrics: Ember.inject.service(),
  actions: {
    sendToMessenger() {
      console.log('send to messenger called')
      var metrics = Ember.get(this, 'metrics')

      var eventData = {
        hitType: 'event',
        eventCategory: 'Outbound Link',
        eventAction: 'click',
        eventLabel: 'Sent to messenger!',
        eventValue: 'https://www.messenger.com/t/heyimlea'
      };

      // if (navigator.sendBeacon) {
      //   //https://github.com/googleanalytics/autotrack/blob/bcdd409c22430553a2a43275386877bf37600e68/lib/plugins/outbound-form-tracker.js#L77
      //   //https://developer.mozilla.org/en-US/docs/Web/API/Navigator/sendBeacon
      //   eventData.transport = 'beacon'
      //   metrics.trackEvent(eventData)
      //   //metrics.trackPage({page: '/sent2messenger', title: "exiting to messenger" });
      //   //be sure analytics.js calls sendBeacon before exiting
      //   setTimeout(exitToMessenger, 4)
      // } else {
        eventData.hitCallback = exitToMessenger;
        metrics.trackEvent(eventData)
      // }
    }
  }

Searching something along the lines of 'analytics track outbound link' I find this help article from google analytics suggesting this method: https://support.google.com/analytics/answer/1136920?hl=en
Here's the docs on hitCallback: https://developers.google.com/analytics/devguides/collection/analyticsjs/sending-hits#hitcallback

I'd love to get this fixed and tested asap so that the ember community can have one comprehensive addon for analytics

[devinrhode2]

Even using the trackPage function doesn't work:

        metrics.trackPage({
          page: '/sent2messenger',
          title: 'sent2messenger',
          hitCallback: exitToMessenger
        })

[devinrhode2]

Also I think it'd be good to take whatever my solution ends up being and add it to an #Extra Examples section around the bottom of the readme (figuring out the eventCategory, eventAction, etc keys was a little tricky)

[devinrhode2]

fix pending merge here: #103