Add native to platform

[ghost]

see portable-scala/sbt-crossproject#17

[Alistair-Johnson]

As my Linux box is bust, I'm on a low memory windows machine, so blocked by scala-native/scala-native#113

In any case, blocked by typelevel/scalacheck#396

[lolgab]

I've published the artifact under my groupid having seen no interest about Scala Native by scalacheck maintainer. You can use "com.github.lolgab" %%% "scalacheck" % "0.4.1" as Scala Native scalacheck dependency.

[s5bug]

What's the status of this issue currently? Has any work been done after the Scalacheck migration?