Create test that runs the notebooks once every month

[martinvonk]

Allright I did a few things:

• Create a test to run the notebooks with _sol. This can also be run locally via pytest .github/workflows/test_notebooks.py
• Update some of the notebooks in order for them to run again (related to pylab, notebook v3, old numpy versions etc.)
• Remove 3 old .ipynb_checkpoints

[martinvonk]

Okay I tweaked this PR and now all notebooks are updated and tested. Also running the test on the first day of the month works.

[mbakker7]

Thanks, @martinvonk !
As you saw, there was quite some maintenance to be done. I appreciate your help.

[mbakker7]

Ready to go?

[martinvonk]

Yes ready to go now. All tests pass :)

[mbakker7]

How do you run a test on notebooks7_bugs? A this notebook throws a bunch or errors.... (and it should!)

[martinvonk]

How do you run a test on notebooks7_bugs? A this notebook throws a bunch or errors.... (and it should!)

In pytest you can run something and check if errors are raises with:

with pytest.raises(Exception):
    run_bugs_notebook()

and then the tests pass only if an Exception is raised.