TEST: Add BaseTestCase class to skip TestCases starting with _

[effigies]

No description provided.

[codecov]

Codecov Report

Merging #871 into pytest will increase coverage by 0.03%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           pytest     #871      +/-   ##
==========================================
+ Coverage   81.59%   81.62%   +0.03%     
==========================================
  Files          97       97              
  Lines       12402    12408       +6     
  Branches     2186     2187       +1     
==========================================
+ Hits        10119    10128       +9     
+ Misses       1876     1874       -2     
+ Partials      407      406       -1

Impacted Files	Coverage Δ
nibabel/testing_pytest/__init__.py	78.5% <100%> (+1.27%)	⬆️
nibabel/streamlines/utils.py	100% <0%> (ø)	⬆️
nibabel/streamlines/__init__.py	100% <0%> (ø)	⬆️
nibabel/streamlines/trk.py	81.96% <0%> (ø)	⬆️
nibabel/dft.py	80.98% <0%> (ø)	⬆️
nibabel/streamlines/tck.py	80.74% <0%> (ø)	⬆️
nibabel/streamlines/tractogram.py	75.56% <0%> (ø)	⬆️
nibabel/streamlines/array_sequence.py	69.93% <0%> (ø)	⬆️
nibabel/freesurfer/io.py	94.22% <0%> (ø)	⬆️
nibabel/streamlines/tractogram_file.py	95% <0%> (ø)	⬆️
... and 39 more

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[effigies]

Cancelled the tests because they're going to ❌ anyway. See https://travis-ci.com/nipy/nibabel/jobs/283443185 to verify that new failures aren't happening.

[djarecka]

@effigies - looks like everything is working, the only thing worries me that when you run tests like nibabel/tests/test_analyze.py, there are many SKIPPED reports, because of the _TestLabeledWrapStruct. Not sure if this was the same with nose

[effigies]

Yeah, I tried to get rid of them, but couldn't. One option is to del the class after using it, but I'm not sure it's worth it.

[djarecka]

yes, probably not worth it.
I believe we even had this discussion about del in DC. remember that was talking to you about my issues with this class in general