This adds fedora-motd package to ostree.
@walters any reason we do not pull this in? at least for rawhide
I had feedback here: https://lists.projectatomic.io/projectatomic-archives/atomic-devel/2016-April/msg00017.html
Not sure if it's all addressed. I glanced at the recent code and I'm still opposed to executing rpm-ostree out of PAM. I'd really only want rpm-ostree to be invoked only if it's been invoked before.