Initial Client/Server Communication

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

Assets/Scripts/MessagePack/Nil.cs

@@ -0,0 +1,38 @@
+// Copyright (c) All contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using System;
+using System.Buffers;
+
+namespace MessagePack
+{
+#if MESSAGEPACK_INTERNAL
+    internal
+#else
+    public
+#endif
+    struct Nil : IEquatable<Nil>
+    {
+        public static readonly Nil Default = default(Nil);
+
+        public override bool Equals(object obj)
+        {
+            return obj is Nil;
+        }
+
+        public bool Equals(Nil other)
+        {
+            return true;
+        }
+
+        public override int GetHashCode()
+        {
+            return 0;
+        }
+
+        public override string ToString()
+        {
+            return "()";
+        }
+    }
+}