Output gathering

https://exercism-team.slack.com/archives/C021B446U9X/p1620900952012300

> I mean it's logging like `@exercism/JavaScript: something` so it can parse out something

So:

- capture output
- split by lines
- loop over lines and assign groups of output (if any) to it's associated test

Another idea:

- being able to "steal" or even observe StdOut stream/buffer