.NET Core Support

[nullif]

Do you plan on releasing a nuget version which works with .net core?

[RyannosaurusRex]

I am working on this here -> https://github.com/RyannosaurusRex/AxosoftAPI.NET

Currently I have it building and unit tests running and passing under .NET core (library is netstandard2.0, but can probably be even lower).

Next steps are to make sure it can package properly.

@schinizel Can you take a look or whoever owns this library? I can make a PR if you want, though I'm not sure about the CI around the package yet. The .sln references the 2 new AxosoftAPI.Net.Core.csproj and AxosoftAPI.Net.Core.Tests.csproj files now for comparison that are .net core and for the most part just reuse the original files with some dependency updates for .net core.

Hopefully we can get this out on NuGet as I'm building a .NET Core app that uses this API and we have an internal wrapper that uses this library that we could reuse. Just let me know what I can do to help. 👍