Add support for abc.abstract* methods

[jrbourbeau]

This PR adds support for abc.abstractproperty, abc.abstractclassmethod, and abc.abstractstaticmethod. The changes here are mostly a duplicate of what was proposed in #369 by @KristianHolsheimer plus a copy of the tests added in #371, but using the abc.abstract* methods. Additionally, this PR extends test_abc a bit to include coverage for abstract @propertys.

As pointed out in #367 (comment), the abc.abstract* methods added here are now deprecated, but it seems reasonable to add support for them anyways as users will still run into them from time to time (xref #394)

Closes #367

[codecov]

Codecov Report

Merging #450 (2f97c6d) into master (6099fdb) will increase coverage by 0.04%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master     #450      +/-   ##
==========================================
+ Coverage   92.52%   92.56%   +0.04%     
==========================================
  Files           4        4              
  Lines         709      713       +4     
  Branches      151      155       +4     
==========================================
+ Hits          656      660       +4     
  Misses         32       32              
  Partials       21       21              

Impacted Files	Coverage Δ
cloudpickle/cloudpickle_fast.py	96.91% <100.00%> (+0.03%)	⬆️

---

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 6099fdb...2f97c6d. Read the comment docs.

[ogrisel]

LGTM. Could you please document the change in the changelog?

[KristianHolsheimer]

Thanks for fixing this @jrbourbeau

[jrbourbeau]

Thanks for reviewing @ogrisel @KristianHolsheimer -- just pushed up a changelog entry

[jrbourbeau]

Just checking in here, @ogrisel is there anything else that should be added to this PR?

[jakirkham]

Sounds like the changelog entry was all that was needed, which has since been added. So going to go ahead and merge. Though please let us know if we missed anything else and we can follow up :)

[ogrisel]

Sorry for the lack of reply. Too many github notifications. Thanks for the PR @jrbourbeau and merging it @jakirkham.

[jakirkham]

No worries. Know the feeling ;)

[jrbourbeau]

Yeah, no worries at all -- you're in good company : )