Add Docker plugin test

[gtrkiller]

Applicable spec:

Overview

Add an integration test for the docker-build-publish plugin.

Rationale

We need to keep track of plugin functionality when updating the charm

Juju Events Changes

N/A

Module Changes

N/A

Library Changes

N/A

Checklist

• The charm style guide was applied
• The contributing guide was applied
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation is generated using src-docs
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex)

[yanksyoon]

LGTM!

[github-actions]

Test coverage for 5a37e20

Name               Stmts   Miss Branch BrPart  Cover   Missing
--------------------------------------------------------------
src/actions.py        29      0      4      0   100%
src/agent.py          93      0     12      0   100%
src/charm.py          88      0     14      0   100%
src/cos.py            21      0      0      0   100%
src/ingress.py         9      0      0      0   100%
src/jenkins.py       336      0     60      0   100%
src/state.py         107      0     24      0   100%
src/timerange.py      31      0      6      0   100%
--------------------------------------------------------------
TOTAL                714      0    120      0   100%

Static code analysis report

Run started:2024-01-23 14:30:57.388949

Test results:
  No issues identified.

Code scanned:
  Total lines of code: 5667
  Total lines skipped (#nosec): 4
  Total potential issues skipped due to specifically being disabled (e.g., #nosec BXXX): 0

Run metrics:
  Total issues (by severity):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
  Total issues (by confidence):
  	Undefined: 0
  	Low: 0
  	Medium: 0
  	High: 0
Files skipped (0):