Code coverage

[cscherrer]

It can be useful to have a quick reference for a given PR telling about changes in code coverage. For example, codecov seems nice for this, though there are many others.
https://about.codecov.io/tool/pytest/

Let's see about getting something like this set up.

[SamWitty]

It looks like the master branch has some code coverage utilities built into the testing suite. @cscherrer could you try pulling from master and running ./scripts/test.sh and see if that satisfies what you're looking for here?

[cscherrer]

Thanks @SamWitty, I should have been more specific about the goal of this. What I'd really like is some indication of changes in code coverage for a given PR, ideally just provided by some bot as a comment on the PR. According to @eb8680 , things had previously been set up this way, but it was disabled because any reduction in coverage was leading to lots of annoying email messages.

So ideally we could have

• A bot that computes code coverage differences for a given PR, and
• provides a useful summary as a comment in that PR, but
• doesn't spam us about it