First cut ListNetworks
move filter implementation to its own package, put it behind an interface
use real NewFilter func in tests
Merge branch 'master' into listnetworks-maas
Merge branch 'master' into uniter-extract-filter
Merge branch 'master' into listnetworks-maas
Skeleton test for ListNetworks
Updated comment and logging
Add comments to test
Refactor Actions to use UUID instead of Sequence

First step in process of consolidating Actions and ActionResults.
Also part of exposing UUID to end clients rather than the Sequence
id that was not guaranteed to reflect order of enqueing.

A couple of other tweaks to avoid calling code that might panic in
non testing code.
address review feedback
Fix test
Merge pull request #1140 from johnweldon/1-action-sequence-to-uuid

Refactor Actions to use UUID instead of Sequence

First step in process of consolidating Actions and ActionResults.
Also part of exposing UUID to end clients rather than the Sequence
id that was not guaranteed to reflect order of enqueing.

A couple of other tweaks to avoid calling code that might panic in
non testing code.
Merge pull request #1130 from voidspace/listnetworks-maas

ListNetworks maas

An implementation of Envrion.ListNetworks for the MaaS provider. It fetches the available networks for a given instance.
add doc comments to Filter interface
Merge pull request #1128 from fwereade/uniter-extract-filter

Uniter: extract Filter

This is trivial: I just put it behind an interface, moved it to its own package, and put the tests in a _test package.
WIP action supercommand: registered with main
WIP action defined subcommand: needs testing
WIP defined testing
WIP juju action do: needs testing, builds and passes