CI Coverage

[ivirshup]

It would be good to have CI track coverage, so we know what is and isn't being tested.

As an example of usefulness, #8 breaks some stuff that isn't covered by tests.

[gtca]

Thanks, there's this available from codecov.io now, and I've also added this workflow to update it.

[ivirshup]

Could this run for PRs to? It's nice to see whether someone's additions are tested.

[gtca]

I am not sure this adds a coverage comment in the pull request thread though yet.

[ivirshup]

Might be hard to tell for a bit, looks like codecov may be down at the moment. From my PR:

[2021-12-15T19:30:25.628Z] ['error'] There was an error running the uploader: Error uploading to https://codecov.io: Error: There was an error fetching the storage URL during POST: 503 - Service Unavailable - upstream connect error or disconnect/reset before headers. reset reason: local reset