dillon1000/react

Remove rootNode from componentDidMount and componentDidUpdate

We can already access the DOM node using `this.getDOMNode()`. Passing it as an argument was a bad decision.

Previous API:

```
componentDidMount(DOMElement rootNode)
componentDidUpdate(object prevProps, object prevState, object prevContext, DOMElement rootNode)
```

Next API:

```
componentDidMount()
componentDidUpdate(object prevProps, object prevState, object prevContext)
```