Fix inconsistencies

[AdamRJensen]

Enforce the usage of the following terminology in pvlib iotools inputs: start/end, latitude/longitude, and metadata. Also, location information (such as latitude/longitude or station name) should come before start/end.

• Closes Inconsistencies in iotools #1245 Closes Add map_variables argument to get_pvgis_tmy #1250
• I am familiar with the contributing guidelines
• Updates entries to docs/sphinx/source/api.rst for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels and Milestone are assigned to the Pull Request and linked Issue.

[kandersolar]

Thanks for this cleanup @AdamRJensen! Comments below, and two more here:

• We'll have to update the existing PVGIS tests at some point before 0.10, might as well specify map_variables=False now so that it's not emitting warnings in the mean time.
• introtutorial.rst uses pvlib.iotools.get_pvgis_tmy, might as well use map_variables=True there too since it does the same thing manually anyway.

[AdamRJensen]

Thanks for the review @kanderso-nrel. Consider all changes implemented.

I've added variable_map=False to all pvgis_tmy tests and they are silent now.

I'm beginning to see something beautiful about the code review process - it truly does make for much better and consistent code.

[kandersolar]

LGTM, would be good to get someone else's (@wholmgren?) feedback too because breaking changes are always scary.

[wholmgren]

Thanks @AdamRJensen. Check out the code below for an example of using fail_on_pvlib_version

pvlib-python/pvlib/tests/test_modelchain.py

Lines 1781 to 1788 in 0fd5c43

	@fail_on_pvlib_version('1.0')
	def test_ModelChain_attributes_deprecated_10(sapm_dc_snl_ac_system, location):
	match = 'Use ModelChain.results'
	mc = ModelChain(sapm_dc_snl_ac_system, location)
	with pytest.warns(pvlibDeprecationWarning, match=match):
	mc.aoi
	with pytest.warns(pvlibDeprecationWarning, match=match):
	mc.aoi = 5

While you're at it, can you change that decorator argument to '0.10'?

[wholmgren]

We need to test that this warning is emitted and mark that test with the fail_on_pvlib_version decorator. This ensures that we don't forget to remove deprecated functionality.

[AdamRJensen]

@wholmgren Very smart, thanks for showing me this!

I believe all of your comments have been addressed.

[wholmgren]

@kanderso-nrel ready to merge?