login opens Snapchat's OAuth screen in-app or through a browser if
Snapchat is not installed. It will then return the logged in SnapchatUser
An error will be thrown if something goes wrong
verifyPhoneNumber verifies if the phoneNumber passed
matches the phone number of the currently signed in
user in the snapchat app. Always returns false on
Android. A two character region code and phoneNumber
must be passed
platformVersion returns a String of the current platform
the appplication is running on, it usally includes both the
Operating System name eg (iOS / Android) and the Version
Number eg (15 / 12)