Z3c.dependencychecker

-----------------

- Fix, hopefully finally, the Zope user mapping use case.
[gforcada]

- Add `Plone` as an umbrella distribution, alongside `Zope`.
[gforcada]

- Scan the `<implements` directive on `ZCML` files.
[gforcada]

- Handle new distributions that no longer have a `setup.py`.
Consider `pyproject.toml` and `setup.cfg` alongside `setup.py`.
[gforcada]

-----------------

- Ignore `node_modules` and `__pycache__` folders
when scanning for files with dependencies.
[gforcada]

- Do not scan Plone FTI files for behaviors with dotted names.
[gforcada]

-----------------

- Do not ignore `Zope` user mappings, fixes previous release.
[gforcada]

----------------

- Ignore `Zope` package, as otherwise it swallows all `zope.` namespace packages.
[gforcada]

----------------

- Drop python 2.7 support.
[gforcada]

- Replace travis for GitHub actions.
[gforcada]

- Test against python 3.7-3.11 and pypy3.
[gforcada]

- Updated developer documentation.
[reinout]

----------------

- Fixed the 'requirement should be test requirement' report. There were corner
cases when using user mappings.
[gforcada]