Rename to Octokit to be consistent with other API libs

GitHub is naming all of the libraries Octokit for their respective
platforms

Octokit/Http/SimpleJsonSerializer.cs

@@ -0,0 +1,25 @@
+namespace Octokit.Http
+{
+    public class SimpleJsonSerializer : IJsonSerializer
+    {
+        readonly GitHubSerializerStrategy serializationStrategy = new GitHubSerializerStrategy();
+
+        public string Serialize(object item)
+        {
+            return SimpleJson.SerializeObject(item, serializationStrategy);
+        }
+
+        public T Deserialize<T>(string json)
+        {
+            return SimpleJson.DeserializeObject<T>(json, serializationStrategy);
+        }
+
+        class GitHubSerializerStrategy : PocoJsonSerializerStrategy
+        {
+            protected override string MapClrMemberNameToJsonFieldName(string clrPropertyName)
+            {
+                return clrPropertyName.ToRubyCase();
+            }
+        }
+    }
+}