Merge pull request #165 from RogueException/issues/159

SocketSelfUser inherits ISelfUser

src/Discord.Net/WebSocket/Entities/Users/SocketSelfUser.cs

@@ -6,7 +6,7 @@ using Model = Discord.API.User;
 
 namespace Discord
 {
-    internal class SocketSelfUser : SelfUser, ISocketUser
+    internal class SocketSelfUser : SelfUser, ISocketUser, ISelfUser
     {
         internal override bool IsAttached => true;