feat(ci): remove codecov step from tox since performed in GA

[StephenSorriaux]

Why is this needed?

There is no need to perform the non-working codecov step via tox since we now have a Github Actions step that performs it.

Proposed Changes

• update tox.ini and remove codecov related stuff
• update GA testing.yml to remove codecov from matrix

Does this PR introduce any breaking change?

Nah.

[codecov]

Codecov Report

Patch coverage has no change and project coverage change: +0.11 🎉

Comparison is base (6dbf606) 96.28% compared to head (10daa15) 96.39%.

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #719      +/-   ##
==========================================
+ Coverage   96.28%   96.39%   +0.11%     
==========================================
  Files          27       27              
  Lines        3554     3554              
==========================================
+ Hits         3422     3426       +4     
+ Misses        132      128       -4     

see 4 files with indirect coverage changes

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[jeffwidman]

👍

To run coverage locally, someone doesn't need to specify anything beyond coverage, right? No extra env vars / flags? Or do they need to specify coverage -e ZOOKEPER_VERSION?

[jeffwidman]

It looks like previously we ran coverage separately for each matrix entry... so removing this we'll only run it once, which means we lose visibility if a particular python/ zookeper version combo loses coverage unexpectedly due to a special casing in the code...

I personally think that's fine, coverage is more a "nice-to-have" tool to surface things, and rather have it run quickly than exhaustively, but wanted to document this.

[StephenSorriaux]

Great point. I am not sure if that coverage for each matrix entry has ever worked, or if I broke something when switching to GA. Looking at the codecov history (https://app.codecov.io/gh/python-zk/kazoo/pulls?order=ASC) does not really help, but I don't remember seeing 20+ comments from codecov in PRs from old Travis times...
Anyway, I agree with you, 1 time per PR seems good enough.

[StephenSorriaux]

+1

To run coverage locally, someone doesn't need to specify anything beyond coverage, right? No extra env vars / flags? Or do they need to specify coverage -e ZOOKEPER_VERSION?

Locally, if you want to use coverage you would just need to perform coverage xml, yes.
FWIW coverage is "integrated" with pytest, in the tox.ini configuration (the pytest-cov dep + the --cov and --cov-report flags).