Update pvfactors to v1.0.1

[anomam]

pvlib python pull request guidelines

Thank you for your contribution to pvlib python! You may delete all of these instructions except for the list below.

You may submit a pull request with your code at any stage of completion.

The following items must be addressed before the code can be merged. Please don't hesitate to ask for help if you're unsure of how to accomplish any of the items below:

• Closes pvfactors 1.0.0 breaks bifacial.pvfactors_timeseries #699
• I am familiar with the contributing guidelines.
• Fully tested. Added and/or modified tests to ensure correct behavior for all reasonable inputs. Tests (usually) must pass on the TravisCI and Appveyor testing services.
• Updates entries to docs/sphinx/source/api.rst for API changes.
• Adds description and name entries in the appropriate docs/sphinx/source/whatsnew file for all changes.
• Code quality and style is sufficient. Passes LGTM and SticklerCI checks.
• New code is fully documented. Includes sphinx/numpydoc compliant docstrings and comments in the code where necessary.
• Pull request is nearly complete and ready for detailed review.

Brief description of the problem and proposed solution (if not already fully described in the issue linked to above):
pvfactors had a major release with an updated package API: so need to update implementation in pvlib-python

[anomam]

Hi @wholmgren , here is a first pass at updating pvfactors in pvlib. Please let me know if you have any questions

[wholmgren]

Thanks @anomam! Looks good to me except for a note about the API changes.

Any comments from people using bifacial models?

[wholmgren]

Please note the breaking API changes in the API section of this file.

[cwhanse]

default is 2 or is -1?

[wholmgren]

@anomam I suggest splitting the run_parallel_calculations=False|True into two tests. Maybe something like this (including optional xfail if you don't know the reason for windows failures).

from conftest import platform_is_windows

@pytest.mark.parametrize('run_parallel_calculations', [
    False,
    pytest.param(True, marks=pytest.mark.xfail(platform_is_windows)
])
def test_pvfactors_timeseries(run_parallel_calculations):
    # modify test as needed for arg

[wholmgren]

Thanks @anomam!