Expect multi-region MAAS clouds

The cloud model in Juju is straightforward - clouds have regions which have AZs. But MAAS is somehow different, there isn't quite the same "region" concept in the clouds, they seem to go straight from 'cloud' to endpoint, skipping the region in the middle.

But MAAS is intended to be multi-region, which is why we call it maas-regiond :)

So I would expect a clouds.yaml more like the following:

clouds:
  garage:
    regions:
      lhr:
        endpoint: http://192.168.2.54/MAAS
      bos:
        endpoint: http://...
      nyc:
        endpoint: http://...

And then:

  $ juju list-clouds
  Cloud Type Regions
  ...
  garage maas bos, lhr, nyc