Propagate parameters on calcparams_cec call (#1215)

[Peque]

• Closes pvsystem.calcparams_cec() does not propagate parameters #1215
• I am familiar with the contributing guidelines
• Tests added
• 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`).
• New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• 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.

Not sure if tests are required (if so, which tests would be appropriate?). Not sure if an update to "whatsnew" is required.

[kandersolar]

For testing pass-through arguments we typically use the mocker fixture with assert_called_with like this: https://github.com/pvlib/pvlib-python/blob/master/pvlib/tests/test_modelchain.py#L1633-L1639

The failing tests are unrelated; looks like the PVGIS copyright text just changed again.

[Peque]

@kanderso-nrel Thanks!

I also added a comment in #776, since I think lint checks could help preventing these types of errors. 😊

[cwhanse]

Thanks @Peque

Any changes to the CI tools (linting) should be proposed in a separate PR.

[wholmgren]

New/better test would be great but optional since this is straightforward and I'm not too concerned about a regression. Definitely should note it in the whats new file.

[Peque]

@kanderso-nrel @wholmgren @cwhanse Added test and a short line in whatsnew.

Thanks for your feedback! 😊 👍

[Peque]

I'll have a look at Python 3.6 and 3.7 failures!

[Peque]

Should be fixed now. 😊

[kandersolar]

Thanks and good catch @Peque!

[wholmgren]

can this be merged?