More test and warning fixes

[rillian]

• Port deprecated yield tests to restore coverage.
• Clean up many of the 'invalid escape sequence' warnings from atflex.py.
• Correct a variable shadowing warning.
• Always run slow tests to correct deprecated pytests.global.config warning.

[codecov-io]

Codecov Report

Merging #77 into master will not change coverage. The diff coverage is 100%.

@@           Coverage Diff           @@
##           master      #77   +/-   ##
=======================================
  Coverage   87.14%   87.14%           
=======================================
  Files          27       27           
  Lines         988      988           
=======================================
  Hits          861      861           
  Misses        127      127

Impacted Files	Coverage Δ
pyoracc/model/corpus.py	82.35% <100%> (ø)	:arrow_up:
pyoracc/atf/common/atflex.py	100% <100%> (ø)	:arrow_up:

---

Continue to review full report at Codecov.

Legend - Click here to learn more Δ = absolute <relative> (impact), ø = not affected, ? = missing data Powered by Codecov. Last update 4ea197a...48296b2. Read the comment docs.

[rillian]

Ha! I guess the disabled tests were redundant. :)

[ageorgou]

Thanks @rillian! It looks like the warning is raised by the Python interpreter itself, not pep8/pycodestyle, and it's not because of the unicode sequences but due to patterns like \/ and \.. This is because of a change in version 3.6 (hence why it only appears in the OS X build), which started warning silently about invalid escape sequences. This will become an error in a future version, so it's worth looking into at some point. I've opened #78 to record it.

[ageorgou]

Seems fine - the pytest version can be discussed in #79!

[rillian]

Thanks!