Updated event tracking to work with Universal Analytics (analytics.js)
Added event tracking for Nivo Slider views (billboards and national leadership)
Merge pull request #7 in PA/medicine from hotfix/ga_event_tracking to master

* commit 'd98ee1fa3c69dd53f8ddadecf72e2f9cb03d965d':
  Added event tracking for Nivo Slider views (billboards and national leadership)
  Updated event tracking to work with Universal Analytics (analytics.js)