Support path sources about paket

[theimowski]

I could grab this one. How would we get direct dependencies, and all versions from a local feed? Reading the directory and parsing the nuspec file itself?

Shall we reflect remote and local Nuget feeds with a separate type (union cases)?

[forki]

yes in this case we need to look into the nuspec file.
You might want to copy https://github.com/fsharp/FAKE/blob/master/src/app/FakeLib/NuGet/NugetHelper.fs#L368

Yes we should reflect this in the types. I consider it another PackageSourceTYpe see https://github.com/fsprojects/Paket/blob/master/src/Paket/BasicTypes.fs#L45