Workalendar

- Easter Sunday is a Brandenburg federate state holiday (143), thx uvchik.
- Added Catalonia (145), thx ferranp.
- Use `find_packages()` to fetch package directories in `setup.py` (141, 144).
- use py.test instead of nosetests for tests (146).
- cleanup: remove unused ``swiss.py`` file (147).

- Added Estonia, thx to landler (134),
- Europe-related modules being reorganized, thx to Natim (135),
- Fixed King / Queen's day in Netherlands, thx to PeterJacob (138),
- Added a pull-request template (125),
- Added a Makefile for various dev-related tasks -- installs, running tests, uploading to PyPI... (133).

*Note:* the 0.6.0 was erroneously uploaded ; this v0.6.1 cancels and replaces the v0.6.0.

- Workalendar now being compatible with Python 3.4 and 3.5 (128),
- A new holiday has appeared in Japan as of 2016 (131), thx suhara for the report.

- Added Slovenia, thx to ratek1 (124),
- Added Switzerland, thx to sykaeh (127),

**Sorry, I think I completely broke the 0.4.3 release by trying to delete a naughty file...**

- Added Denmark (117).
- Tiny fixes in the ``usa.py`` module (flake8 + typo) (122)
- Added datetime to date conversion in is_holiday() (118)
- Added function to get the holiday label by date (120)
- Moved from `novapost` to the `novafloss` organization, handling FLOSS projects in People Doc Inc. (116)
- Added Spain 2016 (123)

- Added Luxembourg (111)
- Added Netherlands (113)
- Added Spain (114)
- Bugfix: fixed the name of the Pentecost for Sweden (115)