v8.4.0

[brunobord]

New Calendar

• Added Kenyan calendar, by @KidkArolis (Add Kenyan calendar #484)

Minor fixes

• Fixed Lithuania calendar to use the core flags for Assumption and All Saints (Lithuania uses Assumption day and all saints as FIXED_DAYS #468).
• Fixed Malta calendar ; January 1st was already included, no need to add it to the FIXED_HOLIDAYS property (Malta: why is there New Year's Day? #469).
• Small refactor in Netherlands calendar to use core constants (Netherlands uses weekdays as numbers instead of core constants #470).

Release task list

• Commit for the tag:
  • Edit version in setup.py
  • Add version in Changelog.md ; trim things
  • Push & wait for the tests to be green
  • tag me.
  • build sdist + wheel packages (make package)
• Back to dev commit:
  • Edit version in setup.py
  • Add the "master / nothing to see here" in Changelog.md
  • Push & wait for the tests to be green
• Merge --ff
• Github stuff
  • Push tag in Github
  • Edit release on Github using the changelog.
  • Delete branch
• upload release on PyPI using twine
• (optional) Make feeback on the various PR or issues.