Configure Google Analytics

[glennrfisher]

Use Google Analytics, see ICT codebase for some shortcuts.

• [x] Send events when user minimizes app (AppDelegate methods)
• [x] Want to be able to describe average session of a user, and how many of them are there (users).
  • [x] Average session lengths and how many users.
• [x] Average number of things in stream, average number of people in stream
• [ ] (not available) Average content length
• [x] Capture count of every major button click
• [ ] Steambot data (when added)
• [ ] WEBSITE-- visitors, dwell time, download on iTunes, all buttons

Related Issue: #71

Also please give Nathan the credentials to view analytics dashboard.

[glennrfisher]

Created #318 and commented in #54 to help track the remaining items.