Bump Newtonsoft.Json from 9.0.1 to 13.0.1 in /Projects/Backendless.Test

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 9.0.1 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@9.0.1...13.0.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

Projects/Backendless.Test/packages.config

@@ -3,7 +3,7 @@
   <package id="EngineIoClientDotNet" version="1.0.7" targetFramework="net40" />
   <package id="MSTest.TestAdapter" version="1.3.2" targetFramework="net471" />
   <package id="MSTest.TestFramework" version="1.3.2" targetFramework="net471" />
-  <package id="Newtonsoft.Json" version="9.0.1" targetFramework="net40" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net40" />
   <package id="SocketIoClientDotNet" version="1.0.7.1" targetFramework="net471" />
   <package id="SuperSocket.ClientEngine.Core" version="0.10.0" targetFramework="net40" />
   <package id="System.Collections.Immutable" version="1.4.0" targetFramework="net471" />