Neglected Python.NET in NuGet package

Hi!

As i see [NuGet package for Python.NET](https://www.nuget.org/packages/pythonnet/2.3.0-py35-dotnet) is really old, last updated was in 2017. Could you update NuGet package to the latest version and can you do more maintaining in your NuGet package to be able to download the newest version in all the time?