tests: setup,teardown -> setup_method, etc

[dwhswenson]

Pytest prefers (and now, apparently requires) the use of setup_method instead of setup.

Looks like there was also a problem to fix about newer pytest not liking pytest.warns(None) as a way to indicate that no warnings were issued.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (f276750) 89.27% compared to head (9932e68) 100.00%.

Additional details and impacted files

@@             Coverage Diff              @@
##           master      #133       +/-   ##
============================================
+ Coverage   89.27%   100.00%   +10.72%     
============================================
  Files          13        13               
  Lines        1091      1154       +63     
============================================
+ Hits          974      1154      +180     
+ Misses        117         0      -117     

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[dwhswenson]

This is ready for review and comment. Without review, I will merge this after at least 24 hours, no sooner than Mon 29 Jan 17:00 GMT (11:00 my local).

[dwhswenson]

Noting here that the pytest.warns(None) issue had been previously solved by @sroet in #124, which I hadn't merged. I merged that one, hoping that credit will go where it is due. FWIW, the only difference (character-by-character) in our solutions were a single vs double quote (took @sroet's single) and that I had added a comment (kept my additional comment.)

[sroet]

LGTM, feel free to merge