Update Json.NET to 9.0.1

samples/AntiforgerySample/project.json

@@ -7,7 +7,7 @@
     "Microsoft.AspNetCore.Server.IISIntegration": "1.0.0-*",
     "Microsoft.AspNetCore.Server.Kestrel": "1.0.0-*",
     "Microsoft.AspNetCore.StaticFiles": "1.0.0-*",
-    "Newtonsoft.Json": "9.0.1-beta1"
+    "Newtonsoft.Json": "9.0.1"
   },
   "buildOptions": {
     "emitEntryPoint": true