Bump Newtonsoft.Json from 6.0.4 to 13.0.1 in /samples/PayPalReceiver (#131)

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 6.0.4 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@6.0.4...13.0.1)

---
updated-dependencies:
- dependency-name: Newtonsoft.Json
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

samples/PayPalReceiver/packages.config

@@ -6,5 +6,5 @@
   <package id="Microsoft.AspNet.WebApi.WebHost" version="5.2.2" targetFramework="net452" />
   <package id="Microsoft.CodeDom.Providers.DotNetCompilerPlatform" version="1.0.0" targetFramework="net452" />
   <package id="Microsoft.Net.Compilers" version="1.0.0" targetFramework="net452" developmentDependency="true" />
-  <package id="Newtonsoft.Json" version="6.0.4" targetFramework="net452" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net452" />
 </packages>