Reduce required fsharp.core version

Author: Jimmy Byrd

paket.dependencies

@@ -2,7 +2,6 @@ source https://api.nuget.org/v3/index.json
 
 
 storage: none
-clitool dotnet-fake
 nuget Hopac
 nuget Microsoft.SourceLink.GitHub prerelease copy_local: true
 nuget Microsoft.NETFramework.ReferenceAssemblies copy_local: true # allows for building full framework on macOS/linux without mono