- Update to 1.4.1:

* Restore use of calendar-specific sub-classes in `cftime.num2date`,
`cftime.datetime.__add__`, and `cftime.datetime.__sub__`. The use of them
will be removed in a later release.
* add 'fromordinal' static method to create a cftime.datetime instance
from a julian day ordinal and calendar (inverse of 'toordinal').
* `cftime.date2num` will now always return an array of integers, if the units
and times allow. Previously this would only be true if the units were
'microseconds' (PR #225). In other circumstances, as before, `cftime.date2num`
will return an array of floats.
* Rewrite of julian day/calendar functions (_IntJulianDayToCalendar and
_IntJulianDayFromCalendar) to remove GPL'ed code. cftime license
changed to MIT (to be consistent with netcdf4-python).
* Added datetime.toordinal() (returns julian day, kwarg 'fractional'
can be used to include fractional day).
* cftime.datetime no longer uses calendar-specific sub-classes.
* fix for issue #211 (PR #212) bug in masked array handling in date2num)
* switch from travis/appveyor to github actions for CI/CD (PR #215).
* switch to cython language_level=3 (no more support for python 2) (PR #217).
* add __init__.py to test dir so pytest coverage works again. Add Coveralls
step to github actions workflow to upload coverage data to coveralls.io (PR
#217).
* move package under 'src' directory so cftime can be imported
from install dir (PR #218 - see
https://blog.ionelmc.ro/2014/05/25/python-packaging/#the-structure).
* zero pad years in strtime (issue #194)
* have cftime.datetime constuctor create 'calendar-aware' instances (default is
'standard' calendar, if calendar='' or None the instance is not calendar aware and some
methods, like dayofwk, dayofyr, __add__ and __sub__, will not work). Fixes issue #198.
The calendar specific sub-classes are now deprecated, but remain for now
as stubs that just instantiate the base class and override __repr__.
* update regex in _cpdef _parse_date so reference years with more than four
digits can be handled.
* Change default calendar in cftime.date2num from 'standard' to None
(calendar associated with first input datetime object is used).
* add `cftime.datetime.tzinfo=None` for compatibility with python datetime
(issue #208).
* num2date uses 'proleptic_gregorian' scheme when basedate is post-Gregorian but date is pre-Gregorian
(issue #182).
* fix 1.2.0 regression (date2num no longer works with numpy scalar array inputs, issue #185).
* Fix for issue #187 (have date2num round to the nearest second when within 1
microsecond).
* Fix for issue #189 (leap years calculated incorrectly for negative years in
proleptic_gregorian calendar).
- No longer build for Python 3.6, due to no NumPy.
- Correct license file name.