simon template for examples testing

[sbillinge]

@cadenmyers13 could you make a new PR and try and make a solution that looks more like this to work?

The basic idea is to copy the entire docs/examples directory to the pytest tmdir fixture, then run everything from there.
Please double check that all output files are written to the tmpdir At least in the NI example they are because they write to PWD/... and PWD is Path('__file__').parent, so as long as we discover the *.py file in the tmpdir copy we should be good to go. Nice aspect is that the code for this is super-simple.

Maybe lets add psutils to requirements/tests.txt rather than comment it out in the example. You will have to do the headless thing etc., but I think this could work, something like this.

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[cadenmyers13]

@sbillinge yeah I'll give it a shot. Thanks for the template!