[packages.config] Update to latest Newtonsoft.Json (#368)

Author: mikeharder

openapi-diff/src/modeler/AutoRest.Swagger/packages.config

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="Newtonsoft.Json" version="9.0.1" targetFramework="net45" />
+  <package id="Newtonsoft.Json" version="13.0.3" targetFramework="net45" />
   <package id="YamlDotNet.Signed" version="5.0.0" targetFramework="net45" />
 </packages>