Summary:
Simple and elegant. Now someone can dismiss a keyboard in a way that makes sense.
```js
import { Keyboard } from 'react-native'
// Hide that keyboard!
Keyboard.dismiss()
```
+ docs
Closes https://github.com/facebook/react-native/pull/9925
Differential Revision: D3935357
fbshipit-source-id: ecd2fb5c72c4dd769951d308e9bb6ee5d888052a