Add selinux test from #486
Add selinux test from #486

Signed-off-by: TomSweeneyRedHat <tsweeney@redhat.com>

Closes: #501
Approved by: rhatdan

nalind/buildah,TomSweeneyRedHat/buildah,projectatomic/buildah,TomSweeneyRedHat/buildah,rhatdan/buildah,nalind/buildah,projectatomic/buildah,TomSweeneyRedHat/buildah,rhatdan/buildah,ipbabble/buildah,projectatomic/buildah,rhatdan/buildah,nalind/buildah-1,nalind/buildah-1,ipbabble/buildah,nalind/buildah-1