Fix server-client connection.

Wino.Server/ServerContext.cs

@@ -1,6 +1,7 @@
 using System;
 using Windows.ApplicationModel;
 using Windows.ApplicationModel.AppService;
+using Windows.Foundation.Collections;
 
 namespace Wino.Server
 {
@@ -35,6 +36,13 @@ namespace Wino.Server
             }
         }
 
+        public async void SendMessage()
+        {
+            var set = new ValueSet();
+            set.Add("Hello", "World");
+            await connection.SendMessageAsync(set);
+        }
+
         private void OnConnectionClosed(AppServiceConnection sender, AppServiceClosedEventArgs args)
         {
             // TODO: Handle connection closed.