autoInitEnabled is removed from iOS, should wrap the initialize function

[rnike]

According to the Changelog of facebook-ios-sdk v9.0.0, the autoInitEnabled has been removed, developers should initialize the sdk manually.

TODO
Wrap initialize function for this package, following the instruction

1. The initializeSDK should be wrapped for iOS.
2. For Android should wrap fullyInitialize also.

Workaround
Call initializeSDK from AppDelegate.m in applicationDidFinishLaunching as the document says