Workalendar

Calendars

- Add optional school holidays to Netherlands calendar, by Flix6x (556).
- Add optional carnival to Netherlands calendar.

Documentation

- Moving the `contributing.md` file to the `docs/` directory (573).
- Changed from `setup.py` to a nice `setup.cfg` file, thanks ewjoachim (576).
- Added documentation about class options (572).
- Converted `README.rst` file into `README.md` (575).
- Fixed Pull Request template to reference `setup.cfg` (587).

Other changes

- Switched from Travis CI to Github Actions for CI jobs, thanks to mgu.
- Added support of Python 3.9 (557).
- Changed from `setup.py` to a nice `setup.cfg` file, thanks ewjoachim (576).
- Use the `setup.cfg` file in the key to cache in `ci.yml` file (587).
- [OBSOLETE] Switched from bionic to focal on Travis CI (we've switched to GH actions after that).

New calendars

- Added Spain regions: Andalusia, Aragon, Castile and León, Castilla-La Mancha, Canary Islands, Extremadura, Galicia, Balearic Islands, La Rioja, Community of Madrid, Murcia, Navarre, Asturias, Basque Country, Cantabria, Valencian Community (531).
- Added all ISO codes for Spain regions - thx ainarela for your help on this (531).

Other changes

- Refactored Spain test modules (531).
- Fix Catalonia calendar by removing *Sant Juan* day, which does not appear to be an official holiday (531).
- Improve coverage of `workalendar/core.py` module (546).
- Improve coverage for the Netherlands calendar - Queen's Day (546).
- Improve coverage for the Romania calendar - Liberation day (546).
- Improve coverage for the New Zealand calendar (546).
- Added a tox entrypoint to ensure code is Python 3.6+, using ``pyupgrade`` (566).
- Added the pyupgrade tox job to the test suite, amended contributing documentation (566).

- **Deprecation:** Dropped support for Python 3.5. As of this version, workalendar now requires Python 3.6+ (330).
- Improve coverage of Singapore calendar (546).

- Add ISO code decorator to Catalonia calendar, thanks to jbagot (551).
- Improve coverage of South Africa calendar (546).
- Improve coverage of Brazil calendar (546).
- Improve coverage of Canada (Nunavut) calendar (546).
- Improve coverage of Israel calendar (546).

New calendar

- Added Mozambique calendar by mr-shovel (542).

New feature

- Added iCal export feature, initiated by joooeey (197).
- Fix PRODID pattern for iCal exports: `"PRODID:-//workalendar//ical {__version__}//EN"`, using current workalendar version (543).

New calendar

- Added Monaco calendar by joaopbnogueira (538).

Major changes and bugfixes

- Migrating Labour Day as a worldwide holiday, disabled by default, but activated (to date) for about 50 countries (including label change when necessary), `contributing.md` documentation amended (467).
- Bugfix: Avoid Cesar Chavez Day duplicated shifts by refactoring the California shift rules (528).

Other changes

- Small refactoring for the Colombia / added docstrings & comments to explain why we're not using stock options. Added tests for year 2020 and handling shift exceptions (509).
- Tech: Replace occurrences of `assertEquals` with `assertEqual` to clear warnings (533).
- Use `include_immaculate_conception` flag for Portugal, Brazil, Argentina, Paraguay calendars (529).