Move environment get/set/unset into a subcommand.
Fix up command registration.
First changed tests due to new gopkg.in/yaml.v1 version.
Merge branch 'master' of https://github.com/juju-actions/juju into fix-yaml-v1-tests
separate metrics code/tests; move helpers from uniter_test to util_test
drop uniter_old_test, move components into uniter_test and util_test as appropriate
Fixes after review.
remove extra quotes
Remove unneeded imports.
Merge branch 'master' of https://github.com/juju-actions/juju into fix-yaml-v1-tests
Split into text, YAML and JSON tests and used the new checkers.
Merge branch 'master' of https://github.com/juju/juju into fix-yaml-v1-tests
testing: Update MakeEnvironment to take CofingAttrs

Update the testing factory function MakeEnvironment to take a new parameter: ConfigAttrs. ConfigAttrs is a map of environment configuration attributes which override the factory defaults.
Fixed newline in test data.
Merged master and changed PR after initial reviews.
Add network.ParsePortRangePort.
ParsePortRangePorts -> ParsePortRange.
Add network.ParsePortRanges.
Add a round-trip test for PortRange strings.
Move ParsePortRange into portrange.go.