support Scala 2.12

[xuwei-k]

• tubesocks Scala 2.12.0 final softprops/tubesocks#5
• dispatch

[mfirry]

Also maybe specs2, right?

[hamnis]

Dispatch cannot be upgraded since it has a dependency to unfiltered which in turns depends on dispatch.

Both for tests.

I suggest dropping dispatch for tests and instead go for either AHC directly, or maybe OkHttp.

[hamnis]

upgrades needed:

• scalatest
• json4s
• scalacheck

I have fixed most issues here, but this is on a snapshot of softprops/tubesocks

hamnis@fbd78b9

[SethTisue]

if Unfiltered is now available for 2.12, can someone submit a PR on https://github.com/scala/make-release-notes/blob/2.12.x/projects-2.12.md removing it from the list at the bottom and adding it to the list at the top...?

[omarkilani]

@SethTisue is it okay if the version is "0.9.0-beta2"?

[SethTisue]

sure

[hamnis]

scala/make-release-notes#251