title: Get all room name in socket.io
body: <p>im using socket.io v1.3.5 to create chat room, now i have a code:</p>
  
  <pre><code>console.log(socket.rooms);
  </code></pre>
  
  <p>It get output:</p>
  
  <pre><code>[ 'pBtWJZqN23xAJw0sAAAE', 'test' ]
  [ 'GPnwtq3gi9t1RZcCAAAD', 'Lobby' ]
  [ 'n7tTlvoH1M7foT3ZAAAC', 'Lobby' ]
  </code></pre>
  
  <p>i had 3 socket.id in 2 room 'lobby' and 'test'. I want to get an array of room name like this:</p>
  
  <pre><code>var listroom = ['Lobby','test']
  </code></pre>
  
  <p>Tks for read.</p>