Update workalendar to 2.4.0

[pyup-bot]

This PR updates workalendar from 2.3.1 to 2.4.0.

Changelog

2.4.0

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

New Calendars
~~~~~~~~~~~~~

- Added Lithuania, by landler (254).
- Added Russia, by vanadium23 (259).

Bugfixes
~~~~~~~~

- Fixed shifting ANZAC day for Australia states (249).
- Renamed Australian state classes to actual state names(eg. AustraliaNewSouthWales to NewSouthWales).
- Update ACT holidays (251).
- Fixing Federal Christmas Shift ; added a `include_veterans_day` flag to enable/disable Veteran's day on specific calendar - e.g. Mozilla's dedicated calendar (242).

Other
~~~~~

- **Deprecation:** Dropped support for Python 3.3 (245).
- Fixed Travis-ci configuration for Python 3.5 and al (252).
- Moved from `novafloss` to the `peopledoc` organization, the core People Doc Inc. organization (255).
- First step iteration on the "global registry" feature. European countries are now part of a registry loaded in the ``workalenda.registry`` module. Please use with care at the moment (248).
- Refactored Australia family and community day calculation (244).

Links

• PyPI: https://pypi.python.org/pypi/workalendar
• Changelog: https://pyup.io/changelogs/workalendar/
• Repo: https://github.com/peopledoc/workalendar

[pyup-bot]

Closing this in favor of #37