Basic atbuild port

To convert to atbuild completely, we need https://github.com/AnarchyTools/atbuild/issues/73
2 jobs for master in 19 seconds (queued for 7 seconds)
Status Job ID Name Coverage
  Package
passed #6630
xcode8symlink carthage
archive-ios

00:00:17

passed #6629
xcode8symlink carthage
archive-mac

00:00:19