Initial Client/Server Communication

#1
Followed the MagicOnion quickstart guide, borrowing code from the chat sample app to get something working

Assets/Scripts/MagicOnion.Abstractions/Server/Hubs/MethodIdAttribute.cs

@@ -0,0 +1,17 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace MagicOnion.Server.Hubs
+{
+    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false, Inherited = true)]
+    public class MethodIdAttribute : Attribute
+    {
+        public readonly int MethodId;
+
+        public MethodIdAttribute(int methodId)
+        {
+            MethodId = methodId;
+        }
+    }
+}