Marnik Bercx

I'll leave this to you, @ramirezfranciscof! Might also be good to mention in a module on dealing with calcjob errors.

@sphuber this is a first working example of converting an `INPUT_PW-{}.xml` file into a JSON schema in `.yaml` format that can then be used to validate the input parameters. Here's...

And deeper down the validation rabbit hole I go... To do some basic testing of which schema accepts which parameters, I've added the `generate_params_from_schema()` function in the `calculations.schemas.utils.py` module. This...

> I have to admit I didn't think this through (so it's probably a bad idea), I'm mostly interested in your thoughts on how to split the interface between generic...

Another note: If we push the `create_magnetic_allotrope` logic down to the `PwCalculation`, it also becomes easier to pass the magnetic configuration between different calculations in a work chain. Currently this...

@CasperWA maybe something to consider putting in another module in the "Data" section?

Note that not all modules need to be executed during the tutorial, but it might be nice to have this on the tutorials page.

This PR superseded #686 @sphuber I'm first going to clean this up and make sure it's properly rebased on `develop`. :)

Changes to regression test files look good in my opinion, i.e. the expected parsed symmetry labels are added. We should still add a test to see if multiple separate `PhCalculation`s...

The code is already in good shape I think (tests still need to be fixed though), but it seems I can't just override the `output_parameters` output with the `self.out()` method....