Open Stack

If you're running nodepool from master, note that when this change
merges, you will need to change your config file and either alter or
drop the node table (to change the 'image_name' column to 'label_name').

  https://review.openstack.org/#/c/82147/

At some point I expect schema migrations and radical ideas like "tests"
to make it into the nodepool repo, but for now it's still a very rough
project and we aren't making any guarantees about being able to run it
CD from master, so be careful if you are.

-Jim