connect method
Implementation
void connect(String id) {
_channel = WebSocketChannel.connect(Uri.parse("ws://skipdq.herokuapp.com"));
// open connection
_stream = _channel.stream.asBroadcastStream();
_stream.listen((event) {});
// send user id to server
_channel.sink.add("{"
"\"message\": \"registerSocket\","
"\"id\": \"$id\""
"}");
}