Support pvlib 0.9.x

[kandersolar]

• Code changes are covered by tests
• New functions added to __init__.py
• API.rst is up to date, along with other sphinx docs pages
• Example notebooks are rerun and differences in results scrutinized
• Updated changelog

Extra to-do:

• Add note to SAPM functions saying an older pvlib is needed

pvlib==0.9.0 is up on pypi as of today. Our current setup.py specifies 'pvlib >= 0.7.0, <0.9.0', but it'd be nice to support the 0.9.x series if it's easy. I think there are only two relevant changes (but we'll see what the CI has to say):

• The SAPM normalization functionality won't work on 0.9.0 because LocalizedPVSystem is removed
• For clear-sky modeling, the tables dependency is removed and h5py is added in its place. Note that h5py is required for pvlib 0.9.0 whereas tables was optional for previous versions.

[mdeceglie]

Looks good to me

[mdeceglie]

What was the reasoning for removing these? Redundant with requirements.txt?

[kandersolar]

[doc] is the requirements to build the sphinx docs, which doesn't actually require any rdtools functionality (e.g. make html does not run the notebooks or tests or anything). So no need to pin specific versions since the packages don't get used for building the docs anyway. And if we're not pinning versions then they're redundant with INSTALL_REQUIRES.