remove irradiance parameter from ModelChain.run_model

[wholmgren]

#239 deprecated the irradiance parameter in ModelChain.run_model. It's time to remove it.

[alamathe1]

@wholmgren Can I please help on this?

[wholmgren]

sure, feel free to make a pull request. I should add that the parameter needs to be removed from ModelChain.prepare_inputs as well.

[alamathe1]

@wholmgren I have removed the irradiance parameter from ModelChain.run_model and ModelChain.prepare_inputs. Is there any preferred tests that needs to be run or shall I raise a PR?

[wholmgren]

It looks to me like the pvlib/test/test_modelchain.py::test_weather_irradiance_input function needs to be removed, but otherwise no changes needed to the tests.

[alamathe1]

@wholmgren Raised #490 Please let me know if there's any modifications required to the PR.