Add a test for USER symlink resolution
Add a test for USER symlink resolution

Add a test that makes sure we catch cases where we attempt to open a
file in the container's tree that's actually a symlink that points out
of the tree.

Signed-off-by: Nalin Dahyabhai <nalin@redhat.com>

Closes: #313
Approved by: rhatdan

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