- Update to 0.20:
* Add localization support, #827 (@arkid15r, @bkthomps, @dragoon)
* Introduce `HolidayBase::_is_leap_year()`, #886 (@arkid15r)
* Introduce `HolidayBase::_is_monday` - `HolidayBase::_is_sunday` helper
methods, #841 (@arkid15r)
* Change holiday name separator from ", " to "; ", #922 (@arkid15r)
* Fix Hong Kong, #928 (@KJhellico)
* Fix Islamic holidays calculation, #914 (@KJhellico)
* Fix Thailand related changes coverage decrease, #942 (@arkid15r, @PPsyrius)
* Improve Thailand holidays, #929 (@PPsyrius, @arkid15r, @KJhellico)
* Update Australia holidays: fix 2020 QLD holidays, #923 (@arkid15r)
* Update Bolivia holidays, #910 (@KJhellico)
* Update Bosnia and Herzegovina holidays, #909 (@KJhellico)
* Update Jamaica holidays, #913 (@KJhellico)
* Update PR template, #960 (@arkid15r)
* Update Poland holidays, add uk localization, #947 (@KJhellico)
* Add International Women's Day for DE-MV, #936 (@alexanderschulze)
* Add Marshall Islands (ISO-3666-1 code MH), #937 (@mborsetti)
* Add Northern Mariana Islands (ISO-3666-2 code US-MP), #939 (@mborsetti)
* ISO 3166-1 for US subdivisions, #941 (@mborsetti, @dr-prodigy)
* Add Albania initial support #895 (@arkid15r)
* Add Andorra initial support #896 (@arkid15r)
* Add Bahrain initial support #888 (@arkid15r)
* Add Montenegro initial support #897 (@arkid15r)
* Add San Marino initial support #898 (@arkid15r)
* Add Vatican City initial support #904 (@arkid15r)
* Add Monaco holidays #877 (@KJhellico)
* Migrate prophet.hdays countries #887 (@arkid15r)
* Singapore holidays update #880 (@KJhellico)
* PyMeeus for equinox and solstice calculation #828, #863 (Nalguedo)