Code review comment for lp://staging/~tribaal/simplestreams/fix-lxd-image-types

For reference, here is the "manual" process we use to get LXD images into OpenStack for use with nova-lxd:

http://bazaar.launchpad.net/~ost-maintainers/openstack-charm-testing/trunk/view/head:/tools/images_lxd.sh

This allows one to successfully nova boot those images as lxd instances, given that there is such a hypervisor in said cloud.