SocketIORouter: Add ability to unregister handler

This will make it easier to add tests.

src/node/handler/SocketIORouter.js

@@ -39,11 +39,13 @@ let io;
  * adds a component
  */
 exports.addComponent = (moduleName, module) => {
-  // save the component
+  if (module == null) return exports.deleteComponent(moduleName);
   components[moduleName] = module;
   module.setSocketIO(io);
 };
 
+exports.deleteComponent = (moduleName) => { delete components[moduleName]; };
+
 /**
  * sets the socket.io and adds event functions for routing
  */