Order resources list.

[anastasiamac]

Description of change

Resources are returned in a map which means that display order is not guaranteed between runs.
This PR ensures that at presentation level, list of resources is always sorted by name in alphabetical order.

This is a pre-cursor to a PR that adds resources featuretest.

QA steps

1. bootstrap
2. run 'juju charm resources' for a charm with multiple resources, several times
   Expected output should be consistently ordered by name.

Documentation changes

n/a

I could not find any juju documentation where 'juju charm resources' command had an output with more than one resource. If such pages exist, they may need to be updated.

Bug reference

Contributes to https://bugs.launchpad.net/juju/+bug/1706809

[anastasiamac]

$$merge$$

Thank you for review, @babbageclunk \o/

[jujubot]

Status: merge request accepted. Url: http://juju-ci.vapour.ws:8080/job/github-merge-juju

[anastasiamac]

@pmatulis,

This change may require documentation update.

[pmatulis]

@anastasiamac Nothing to do here!