Show plugin name in document title

I think this is the most efficient way, so that the name only get's set when we fetch the plugin, and only changed back when the page is updated. Which, since it's React.js, shouldn't happen unless we move to a new page. 
@spicyj So I couldn't call `updateTitle()` in `componentDidMount()` since the `getJSON` call is asynchronous. As a result, I update the title when we get the JSON response. Though since we set the state, in the response, it seems like `componentDidUpdate()` gets called immediately anyway. Would you leave all three `updateTitle()` calls in, or just have them in `componentDidUpdate()` and `componentWillUnmount()`?