.NET Core 2.0 reached EOL last year. This removes multi-targeting our test projects and test assets to only use .NET Core 2.1 and .NET Framework 4.6.1.
This simplifies the way that we publish files to our network drop share.
Changes:
* Instead of explicitly listing every file that needs to publish, use directories to classify packages and artifacts into different categories.
* Add documentation for the expected layout of artifacts/
* Remove the need for static analysis to determine which packages go to which project
* Add the MSBuild property "IsProductPackage" to .csproj files which ship as a package to NuGet.org.