title: Close websocket connection in redux-observable
body: <p>I'm currently using <code>redux-observable</code> to handle a websocket connection but can't figure out what's the best way to handle the <code>close</code> event.</p>
  
  <pre><code>const webSocket$ = Observable.webSocket({
    url: 'ws://localhost:8080'
  });
  
  export const fetchMessagesEpic = (action$) =&gt;
    action$.ofType(FETCH.MESSAGES)
      .switchMap((action) =&gt;
        webSocket$
          .catch((err) =&gt; { console.log(err);return true; }) &lt;-- I can see the close event here
          .map((msg) =&gt; addMessage(msg)));
  </code></pre>
  
  <p>Should I be handling it in <code>catch</code> (sending a new action from there and then using <code>takeUntil</code> in the same epic?</p>