Drop Python 3.5 support, fix CI

[ods]

Changes

• Drop support for Python 3.5
• Revert switch to pytest-asyncio as it doesn't support unittest.TestCase
• Remove compatibility code branches for Python versions we already don't support

Checklist

• I think the code is well written
• Unit tests for the changes exist
• Documentation reflects the changes
• Add a new news fragment into the CHANGES folder
  • name it <issue_id>.<type> (e.g. 588.bugfix)
  • if you don't have an issue_id change it to the pr id after creating the PR
  • ensure type is one of the following:
    • .feature: Signifying a new feature.
    • .bugfix: Signifying a bug fix.
    • .doc: Signifying a documentation improvement.
    • .removal: Signifying a deprecation or removal of public API.
    • .misc: A ticket has been closed, but it is not of interest to users.
  • Make sure to use full sentences with correct case and punctuation, for example: Fix issue with non-ascii contents in doctest text files.

[codecov]

Codecov Report

Merging #667 into master will increase coverage by 50.19%.
The diff coverage is 100.00%.

@@             Coverage Diff             @@
##           master     #667       +/-   ##
===========================================
+ Coverage   47.77%   97.96%   +50.19%     
===========================================
  Files          29       29               
  Lines        5124     5114       -10     
===========================================
+ Hits         2448     5010     +2562     
+ Misses       2676      104     -2572     

Flag	Coverage Δ
#cext	87.48% <100.00%> (+50.01%)	⬆️
#integration	97.92% <100.00%> (+50.19%)	⬆️
#purepy	97.41% <100.00%> (+50.13%)	⬆️
#unit	50.68% <100.00%> (+11.34%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
aiokafka/consumer/consumer.py	97.89% <ø> (+81.52%)	⬆️
aiokafka/producer/producer.py	98.49% <ø> (+56.41%)	⬆️
aiokafka/abc.py	66.66% <100.00%> (-2.09%)	⬇️
aiokafka/conn.py	94.00% <100.00%> (+40.91%)	⬆️
aiokafka/record/default_records.py	95.46% <0.00%> (+0.30%)	⬆️
aiokafka/errors.py	100.00% <0.00%> (+0.69%)	⬆️
aiokafka/record/legacy_records.py	98.86% <0.00%> (+0.75%)	⬆️
aiokafka/record/memory_records.py	100.00% <0.00%> (+5.88%)	⬆️
aiokafka/cluster.py	100.00% <0.00%> (+14.86%)	⬆️
aiokafka/client.py	97.79% <0.00%> (+27.76%)	⬆️
... and 9 more

---

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 84e2a98...98a35fc. Read the comment docs.

[asvetlov]

LGTM but please wait for a little for @tvoinarovskyi review

[tvoinarovskyi]

Hi @ods, thanks for working on this.
Looks good, I am not sure how the python-asyncio addition did not affect my environment, maybe I failed to rebuild something.

[ods]

I am not sure how the python-asyncio addition did not affect my environment, maybe I failed to rebuild something.

pytest.mark.asyncio just doesn't work for unittest.TestCase methods. I'd like to rewrite tests pytest-style (with fixtures and functions), but that's separate task and deserves a separate PR. And after fixing warnings for Python 3.8/3.9

[tvoinarovskyi]

There is a separate branch that removes loop usage called fixpy38 I think. Mostly it's finished aside from a few points that I don't remember any more :)

[tvoinarovskyi]

Feel like we should revert this part. Tests are running 2ce without the limit. I think you use it to run on the fork, right? Maybe there is a better way to configure Actions...

[ods]

Reverted in #669