Relicense from LGPL-3 to BSD-3

[lbdreyer]

All the code in this repo comes from contributors who have now either signed the new CLA or are employees of the Met Office.

The new CLA enables us to relicense to BSD-3.

This PR:

• adds a BSD-3 LICENSE file (to replace the old COPYING* files)
• Updates the pypi classifiers/metadata etc
• Updates the file license headers

[bjlittle]

@lbdreyer Test failure to investigate, but not your doing... 🤔

[rcomer]

I think that test failure is just a method that shouldn't start with "test".

cf-units/cf_units/tests/unit/unit/test_Unit.py

Lines 82 to 94 in 2a164dc

	def test_gregorian_calendar_conversion_setup(self):
	# Reproduces a situation where a unit's gregorian calendar would not
	# match (using the `is` operator) to the literal string 'gregorian',
	# causing an `is not` test to return a false negative.
	cal_str = cf_units.CALENDAR_GREGORIAN
	calendar = self.MyStr(cal_str)
	assert calendar is not cal_str
	u1 = Unit("hours since 1970-01-01 00:00:00", calendar=calendar)
	u2 = Unit("hours since 1969-11-30 00:00:00", calendar=calendar)
	u1point = np.array([8.0], dtype=np.float32)
	expected = np.array([776.0], dtype=np.float32)
	result = u1.convert(u1point, u2)
	return expected, result

Edit: nope, that's just a warning I'm looking at. I'll open a PR to fix the warning anyway....

[pp-mo]

@bjlittle not your doing

Not so sure.

I think the two files mentioned did get missed in updating the licence header.
So, I think these tweaks may fix what was wrong?
Haven't really checked anything else yet, but I'm sure it's right in spirit.

[lbdreyer]

Thanks for catching the problem @pp-mo !

The changes should now be correct

[bjlittle]

👍

[pp-mo]

Re-reviewing this to approve.
But I can't understand why this is necessary, since it lists no unresolved conversations.
Seen this before, I think it is possibly a GitHub bug ??

[lbdreyer]

Thanks @pp-mo !