Run unit tests on CI for MacOS
Run unit tests on CI for MacOS

Though we don't officially support Apple platform, we should
at least run unit tests to make sure things are not broken.

Signed-off-by: Maksym Pavlenko <721705b98eb4b3da8f1cd33abf8d358bd4a6a67a@gmail.com>

mikebrow/containerd,estesp/containerd,thaJeztah/containerd,mikebrow/containerd,containerd/containerd,vdemeester/containerd,containerd/containerd,dmcgowan/containerd,estesp/containerd,vdemeester/containerd,dmcgowan/containerd,thaJeztah/containerd