upgrade pytest

[minrk]

pip has changed its default upgrade strategy, even when --upgrade is specified to leave known-incompatible old versions installed. Switch to --upgrade-strategy=eager to ensure that things are correctly installed.

[lumberbot-app]

Owee, I'm MrMeeseeks, Look at me.

There seem to be a conflict, please backport manually. Here are approximate instructions:

1. Checkout backport branch and update it.

$ git checkout 5.x
$ git pull

2. Cherry pick the first parent branch of the this PR on top of the older branch:

$ git cherry-pick -m1 3fbd4c6b5e36ba6717a71870a47084fc6aa41c8f

3. You will likely have some merge/cherry-pick conflict here, fix them and commit:

$ git commit -am 'Backport PR #421: upgrade pytest'

4. Push to a named branch :

git push YOURFORK 5.x:auto-backport-of-pr-421-on-5.x

5. Create a PR against branch 5.x, I would have named this PR:

"Backport PR #421 on branch 5.x"

And apply the correct labels and milestones.

Congratulation you did some good work ! Hopefully your backport PR will be tested by the continuous integration and merged soon!

If these instruction are inaccurate, feel free to suggest an improvement.