Bump Newtonsoft.Json in /src/Angara.Serialization.Json.Tests

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 10.0.1 to 13.0.2.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](https://github.com/JamesNK/Newtonsoft.Json/compare/10.0.1...13.0.2)

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

Signed-off-by: dependabot[bot] <support@github.com>

src/Angara.Serialization.Json.Tests/packages.config

@@ -2,7 +2,7 @@
 <packages>
   <package id="FsCheck" version="2.2.4" targetFramework="net452" />
   <package id="FSharp.Core" version="3.1.2.5" targetFramework="net452" />
-  <package id="Newtonsoft.Json" version="10.0.1" targetFramework="net452" />
+  <package id="Newtonsoft.Json" version="13.0.2" targetFramework="net452" />
   <package id="NUnit" version="2.6.4" targetFramework="net452" />
   <package id="Unquote" version="2.2.2" targetFramework="net452" />
 </packages>