Added 'ExtraData' to Pr0grammResponse

src/OpenPr0gramm/Response/Pr0grammResponse.cs

@@ -1,6 +1,10 @@
-using Newtonsoft.Json;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
 using OpenPr0gramm.Json;
+
 using System;
+using System.Collections.Generic;
 
 namespace OpenPr0gramm
 {
@@ -11,5 +15,8 @@ public class Pr0grammResponse
         public object Cache { get; private set; }
         public int RT { get; private set; }
         public int QC { get; private set; }
+
+        [JsonExtensionData]
+        public IDictionary<string, JToken> ExtraData { get; private set; }
     }
 }