Add snap support (#60)

* Initial app daemon implementation

* Pass script path to child bridge processes

* Change WebSocket server port

* Fix error sending message whilst WebSocket connection is closing

* Initial ext daemon connection implementation

ext/src/ui/popup/index.tsx

@@ -122,7 +122,7 @@ class PopupApp extends Component<{}, PopupAppState> {
                         <ReceiverEntry receiver={ receiver }
                                        onCast={ this.onCast }
                                        isLoading={ this.state.isLoading }
-                                       key={ i }/> )}
+                                       key={ i }/> ))}
                 </ul>
             </div>
         );