This overwrites the `codecov.yml` file in the root of the repository with
`codecov-upstream.yml` file (which contains the code-cov token)´, so PRs
and branches on the repository can upload coverage.
Suggestion from here:
https://github.com/pytest-dev/pytest/pull/6421#issuecomment-571934112
Security concerns: the token might be misused, but only to upload bogus coverage
to `codecov.io`, so the team believe this is harmless. If we decide to fallback
from this decision , we just need to revoke the token.
Related to #6369
This includes our current full matrix (windows, linux and macos), for evaluting
purposes.
We should disconsider failures when evaluating PRs.
TODO:
- deploy
- coverage
- github release notes
Even with the above missing, I still believe it would be nice to merge
this and have GitHub actions working in parallel so we can evaluate performance
and usability from now on.