Make tests/test_check.py py.test friendly

[lesteve]

First go at tackling #139 one file at a time.

Adding __init__.py in the tests folder is a convenience so that you can do py.test tests/test_check.py. It seems to be a convention in all the projects I have worked with too (numpy, scipy, scikit-learn, etc ...).

[lesteve]

@mmckerns any comments on this one? I completely understand if you don't have much time on your hand but I would have thought this PR would be a quick one to review ...

Just as a reminder the end goal is to be able to run tests with py.test and further down the line to have CI testing on PRs via Travis.

[lesteve]

gentle ping @mmckerns.

[lesteve]

Any comments on this one @mmckerns?

[mmckerns]

@lesteve: sorry I've been swamped for about a month. I will most likely take this PR as is. I prepped an environment to test it, and looked at how others are using py.test… but I've been stuck there for a while. This is of the first things I'll do once I am no longer on fire.

[lesteve]

OK thanks for your reply. I'll try to gather some momentum to tackle other files in a similar way, so that they are py.test friendly as well.

[mmckerns]

@lesteve: I'm going to mark this as duplicate to #198, as #198 handles it in a way uniform to other of the tests. Thanks for your contribution… sorry it took me this long to get to it… and please don't hesitate to help out on the pytest test-runner portion of PR #198.