Add a listenToAll function the NullConnector.

Fixes #366

Author: Marcus

src/connector/null-connector.ts

@@ -24,6 +24,13 @@ export class NullConnector extends Connector {
         return new NullChannel();
     }
 
+    /**
+     * Listen for all events on the channel instance.
+     */
+    listenToAll(callback: Function): NullChannel {
+        return this;
+    }
+
     /**
      * Get a channel instance by name.
      */