code: function PubNubTransport(config) {
    this.id = config.id || null;
    this.networkId = config.publish_key || null;
    this['default'] = config['default'] || false;
    this.pubnub = PUBNUB().init(config);
  }
docs: Use pubnub as transport
  @param {Object} config         Config can contain the following properties:
  - `id: string`. Optional
  - `publish_key: string`. Required
  - `subscribe_key: string`. Required
  @constructor