Json.NET Schema draft 7 support

Author: JamesNK

_data/validator-libraries.yml

@@ -3,7 +3,7 @@
   implementations: 
     - name: Json.NET Schema
       url: https://www.newtonsoft.com/jsonschema
-      draft: [3, 4, 6]
+      draft: [3, 4, 6, 7]
       license: "MIT"
     - name: Manatee.Json
       url: https://github.com/gregsdennis/Manatee.Json