Example for raw websockets

Here's an example for raw websockets (instead of sockjs). It appears that onmessage, onclose, etc, used in the sockjs examples don't apply to raw websockets. 

```
var ws = new WebSocket('ws://' + foo);
var pubsub = new WebSocketMultiplex(ws); 

var logs = pubsub.channel('/logs');
logs.addEventListener('message', function(dataObject) {
  console.log('logs got data ' + dataObject.data);
});
```
