Code review bots?

[fmaussion]

I'm seeing them from time to time on other repositories. One that seems reasonable and not toooo intrusive is stickler, for code style review: https://stickler-ci.com/

[shoyer]

Sure, automated comments on a pull request are definitely friendlier than a failed Travis-CI build.

[shoyer]

Let me know if you don't have the permissions to add it and I should be able to help.

[fujiisoup]

I think we can remove the flake8 test in travis.
It would make clear on github whether tests fail or code style issues.

[Zac-HD]

Per comment on the pull: my experience is that bots are a great complement, but can't replace style checks in CI.

Only remove flake8 from Travis if you're OK with merging pulls that don't meet the style guide (and then amend the contributing guide to match) - that's a valid decision, but also a weaker position than Xarray has previously taken.