Added reference project

ref/Events/MessageUpdatedEventArgs.cs

@@ -0,0 +1,13 @@
+using System;
+
+namespace Discord
+{
+    public class MessageUpdatedEventArgs : EventArgs
+    {
+        public Message Before => null;
+        public Message After => null;
+        public User User => null;
+        public Channel Channel => null;
+        public Server Server => null;
+    }
+}