Add kwargs to forecast.get_data with tests

[odow]

pvlib python pull request guidelines

• Closes forecast.get_data doesn't allow extra kwargs #745
• 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.

Running locally, I get some warnings. Should I fix these? Also, the tests take 60 seconds on my machine which seems a bit long for this one file. Shall I merge some tests? Or any other ideas for speeding it up?

(tonopah) Oscars-MBP:pvlib-python oscar$ pytest pvlib/test/test_forecast.py
============================= test session starts ==============================
platform darwin -- Python 3.7.3, pytest-5.0.0, py-1.8.0, pluggy-0.12.0
rootdir: /Users/oscar/Documents/Code/pvlib-python
plugins: mock-1.10.4
collected 18 items                                                             

pvlib/test/test_forecast.py .....X............                           [100%]

=============================== warnings summary ===============================
/anaconda3/envs/tonopah/lib/python3.7/site-packages/_pytest/mark/structures.py:332
  /anaconda3/envs/tonopah/lib/python3.7/site-packages/_pytest/mark/structures.py:332: PytestUnknownMarkWarning: Unknown pytest.mark.timeout - is this a typo?  You can register custom marks to avoid this warning - for details, see https://docs.pytest.org/en/latest/mark.html
    PytestUnknownMarkWarning,

pvlib/test/test_forecast.py::test_process_data[HRRR_ESRL]
  /Users/oscar/Documents/Code/pvlib-python/pvlib/test/test_forecast.py:56: UserWarning: Exception getting data for GSD HRRR CONUS 3km surface, best.
  latitude, longitude, start, end = 32.2 -110.9 2019-07-02 20:21:41.477024-07:00 2019-07-03 20:21:41.477024-07:00
  Error accessing https://thredds.ucar.edu/thredds/ncss/grib/HRRR/CONUS_3km/surface/Best?var=Medium_cloud_cover_UnknownLevelType-224&var=Total_cloud_cover_entire_atmosphere&var=High_cloud_cover_UnknownLevelType-234&var=Downward_short-wave_radiation_flux_surface&var=Temperature_surface&var=Wind_speed_gust_surface&var=Low_cloud_cover_UnknownLevelType-214&time_start=2019-07-02T20%3A21%3A41.477024-07%3A00&time_end=2019-07-03T20%3A21%3A41.477024-07%3A00&longitude=-110.9&latitude=32.2&accept=netcdf
  Server Error (400: Requested time range 2019-07-03T03:21:41.477Z - 2019-07-04T03:21:41.477Z does not intersect actual time range 2019-06-29T00:01:00Z - 2019-07-02T23:36:00Z)
    .format(amodel, _latitude, _longitude, _start, _end, e))

pvlib/test/test_forecast.py::test_process_data[HRRR_ESRL]
  /Users/oscar/Documents/Code/pvlib-python/pvlib/test/test_forecast.py:67: UserWarning: Could not test GSD HRRR CONUS 3km surface, best process_data with how=liujordan because raw_data was empty
    'because raw_data was empty'.format(model, how))

pvlib/test/test_forecast.py::test_process_data[HRRR_ESRL]
  /Users/oscar/Documents/Code/pvlib-python/pvlib/test/test_forecast.py:67: UserWarning: Could not test GSD HRRR CONUS 3km surface, best process_data with how=clearsky_scaling because raw_data was empty
    'because raw_data was empty'.format(model, how))

-- Docs: https://docs.pytest.org/en/latest/warnings.html
============== 17 passed, 1 xpassed, 4 warnings in 66.84 seconds ===============

• 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.

[cwhanse]

@odow don't worry about the np.maximum/minimum warnings. The test failure you posted appears to be a server not responding. Please merge master now with #748, that should fix the py35-min build failure.

[odow]

So tests are passing, but the codecov failed because these lines weren't hit. I copied them from elsewhere in the file. What is your policy on codecov needing to pass for tests?

[wholmgren]

Looks good, just a few minor things below...

I don't understand why the diff coverage test fails. I think it's ok to ignore it.

[wholmgren]

Ah, I missed your comment when finishing my review. This PR is about fixing an API issue. I don't think it's important that it tests details of the returned data.

[wholmgren]

Thanks @odow!