[Merge] ~toabctl/livecd-rootfs:new-ubuntu-oci into livecd-rootfs:ubuntu/master

[Philip Roche]

Review: Needs Information

Looks great and matches the changes in docker-brew-ubuntu-core/blob/master/update.sh

Can you upload your test image tar.gz to people.canonical.com so we can try it out?
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https://code.launchpad.net/~toabctl/livecd-rootfs/+git/livecd-rootfs-1/+merge/401596
Your team Ubuntu Core Development Team is requested to review the proposed merge of ~toabctl/livecd-rootfs:new-ubuntu-oci into livecd-rootfs:ubuntu/master.