wordpress-mobile/WordPress-iOS — pull request #2803 by sendhil (2014-11-16 00:53:04+00:00)
Title: Added tracking for when a user upgrades app

* Added an event "App Upgrades" to Mixpanel.
* Created people properties to track `last_ios_version` and `current_ios_version`
* Created super properties to track `last_ios_version` and `current_ios_version`