Add feature to skip a test case

[maria-pia-goicoechea-lenio]

Hi, it would be so useful to have the possibility to specify that one test case should be skipped.

[ckp95]

It's a good idea, not sure how to declare it though. There are a few options:

Case(foo=3, bar=f).skip(reason=...)

Case(foo=3, bar=4).mark(pytest.mark.skip(reason=...))

Case(foo=3, bar=4).set_params(marks=pytest.mark.skip(reason=...))

Allowing "skip" opens the door to all kinds of other things that pytest lets you do ...

[ckp95]

see also #3