Consider running FSharpSuite.Tests in parallel

[Youssef1313]

Tests in FSharpSuite.Tests take very long. They might benefit from being parallelized. Are there any known issues today that prevents running them in parallel?

cc @T-Gro @abonie

[majocha]

Yes, it was running in parallel ok with xUnit v2.

[T-Gro]

Sharding in place.