Thoth.Json.Net depends on Fable.Core

[forki]

Thoth.Json.Net (3.5.1)
  Fable.Core (>= 3.0 < 4.0) - restriction: && (< net46) (>= netstandard2.0)
  FSharp.Core (>= 4.6.2) - restriction: || (>= net46) (>= netstandard2.0)
  Newtonsoft.Json (>= 11.0.2) - restriction: || (>= net46) (>= netstandard2.0)

I think this dependency on Fable.Core should be removed.

[MangelMaxime]

This is normal, we need it to support StringEnums

See #148

We include Fable.Core only, for frameworks version supporting it.

[forki]

if I use netcoreapp3.0 then it shouldn't be there, right?

[MangelMaxime]

I don't know, are netstandard2.0 libraries supported by netcoreapp3.0?

For example, if I remember correctly netstandard1.6 was usable from `and co apps.