message: track activity feed events
diff: @@ -4,6 +4,7 @@ import { FiresidePost } from '../../../../lib/gj-lib-client/components/fireside/
  import { Api } from '../../../../lib/gj-lib-client/components/api/api.service';
  import { Notification } from '../../../../lib/gj-lib-client/components/notification/notification-model';
  import { arrayRemove } from '../../../../lib/gj-lib-client/utils/array';
  +import { Analytics } from '../../../../lib/gj-lib-client/components/analytics/analytics.service';
  /**
  * The number of items from the bottom that we should hit before loading more.
  @@ -103,7 +104,7 @@ export class ActivityFeedContainer {
  this.viewedItems.push(item.id);
  if (item.type === 'devlog-post') {
  - const feedItem = <FiresidePost>item.feedItem;
  + const feedItem = item.feedItem as FiresidePost;
  feedItem.$viewed();
  }
  }
  @@ -116,9 +117,11 @@ export class ActivityFeedContainer {
  this.expandedItems.push(item.id);
  if (item.type === 'devlog-post') {
  - const feedItem = <FiresidePost>item.feedItem;
  + const feedItem = item.feedItem as FiresidePost;
  feedItem.$expanded();
  }
  +
  + Analytics.trackEvent('activity-feed', 'expanded-item');
  }
  inViewChange(item: ActivityFeedItem, visible: boolean) {
  @@ -161,6 +164,7 @@ export class ActivityFeedContainer {
  if (!response.items || !response.items.length) {
  this.reachedEnd = true;
  + Analytics.trackEvent('activity-feed', 'reached-end');
  return;
  }
  @@ -169,6 +173,8 @@ export class ActivityFeedContainer {
  } else if (this.feedType === 'Fireside_Post') {
  this.append(FiresidePost.populate(response.items));
  }
  +
  + Analytics.trackEvent('activity-feed', 'loaded-more', 'page-' + this.timesLoaded);
  }
  /**
  