deps: Add lorax

We aren't using it today, but we might use it in the future - or
we may at least share code.

Since this container is enormous anyways, there's no real downside
to adding the dep now.

For more information, see discussion in:
coreos#91

deps.txt

@@ -24,6 +24,8 @@ make git rpm-build
 libvirt libguestfs-tools qemu-kvm /usr/bin/qemu-img /usr/bin/virsh /usr/bin/virt-install
 # And we process kickstarts
 /usr/bin/ksflatten
+# We also might use lorax-composer (livemedia-creator) in the future to make images
+lorax
 
 # ostree-releng-scripts dependencies
 rsync python2-gobject-base python3-gobject-base