Summary:
React 16 is out! Lets gogogo~

![go_time](https://user-images.githubusercontent.com/1114467/30974583-d4a32d3a-a424-11e7-9ef0-76d0dd5efde8.jpg)
Closes https://github.com/facebook/draft-js/pull/1414

Differential Revision: D5932258

fbshipit-source-id: 3fdfe19f65e7f970c9cf89b495e08671b48de4f5