Merge pull request #306 from Inumedia/dependabot/nuget/SlackAPI/Newtonsoft.Json-13.0.1

Bump Newtonsoft.Json from 9.0.1 to 13.0.1 in /SlackAPI

Author: Inumedia

SlackAPI/SlackAPI.csproj

@@ -8,7 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Newtonsoft.Json" Version="9.0.1" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
     <PackageReference Include="System.Net.Http" Version="4.3.4" />
   </ItemGroup>