Code review comment for lp:~fwereade/pyjuju/maas-name-constraint

Reviewers: mp+99746_code.launchpad.net,

Message:
Please take a look.

Description:
Implement maas-name constraint

Descended from lp:~julian-edwards/juju/name-constraints; but uses
new-style
constraints registration.

Also uses a custom ubuntu-series constraint to forbid use of charms
written
for systems we can't yet provision with MAAS.

https://code.launchpad.net/~fwereade/juju/maas-name-constraint/+merge/99746

Requires:
https://code.launchpad.net/~fwereade/juju/constraints-get/+merge/99704

(do not edit description out of merge proposal)

Please review this at https://codereview.appspot.com/5938050/

Affected files:
   A [revision details]
   M juju/environment/config.py
   M juju/environment/tests/test_config.py
   M juju/machine/constraints.py
   M juju/machine/tests/test_constraints.py
   M juju/providers/maas/launch.py
   M juju/providers/maas/maas.py
   M juju/providers/maas/provider.py
   M juju/providers/maas/tests/test_launch.py
   M juju/providers/maas/tests/test_maas.py
   M juju/providers/maas/tests/test_provider.py
   M juju/providers/maas/tests/testing.py