support version=latest

[jonboulle]

aci-discovery should support the version label being set to latest and simply retrieve the latest version of the thing that matches the other supplied labels. Since this is really an example implementation it's not super critical what heuristic it uses behind the scenes - either doing a max(version_labels) or just looking at the latest mtime, or whatever.

[bcwaldon]

Yep. Patches accepted.