Server return status 200 while rendering 404 page

Because of the [catch-all route](https://github.com/erikras/react-redux-universal-hot-example/blob/master/src/routes.js#L55) `match` will always match a route and `renderProps` will always be defined. For this reason, [this branch is never reached](https://github.com/erikras/react-redux-universal-hot-example/blob/master/src/server.js#L105-L107) and the 404 page is [served with a status code of 200](https://github.com/erikras/react-redux-universal-hot-example/blob/master/src/server.js#L98).