Bump Newtonsoft.Json in /Bots/DotNet/EchoSkillBot-v3

Bumps [Newtonsoft.Json](https://github.com/JamesNK/Newtonsoft.Json) from 10.0.2 to 13.0.1.
- [Release notes](https://github.com/JamesNK/Newtonsoft.Json/releases)
- [Commits](JamesNK/Newtonsoft.Json@10.0.2...13.0.1)

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

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

Author: dependabot[bot]

Bots/DotNet/EchoSkillBot-v3/packages.config

@@ -26,7 +26,7 @@
   <package id="Microsoft.Net.Compilers" version="2.0.1" targetFramework="net472" developmentDependency="true" />
   <package id="Microsoft.Rest.ClientRuntime" version="2.3.8" targetFramework="net472" />
   <package id="Microsoft.WindowsAzure.ConfigurationManager" version="3.2.3" targetFramework="net472" />
-  <package id="Newtonsoft.Json" version="10.0.2" targetFramework="net472" />
+  <package id="Newtonsoft.Json" version="13.0.1" targetFramework="net472" />
   <package id="System.Collections" version="4.3.0" targetFramework="net472" />
   <package id="System.IdentityModel.Tokens.Jwt" version="5.1.4" targetFramework="net472" />
   <package id="System.Linq" version="4.3.0" targetFramework="net472" />