Error occur on web

Please change line 42 

from:
`style: ViewPropTypes.style`

into:
 `style: Platform.OS === 'web' ? PropTypes.any : ViewPropTypes.style`

Otherwise there will be a error as follow when displaying on `web`:

```
KeyBoardSpacer.js:42 Uncaught TypeError: Cannot read property 'style' of undefined
```