Figure out why the test suite doesn't finish

[nventuro]

For some time now we've had hangs in the CI, where the build fails because it goes over the maximum time limit, which requires a manual restart. It also sometimes happens locally. @shrugs suggested using https://github.com/mafintosh/why-is-node-running to find the root cause.

[jbogacz]

Hey @nventuro don't you fortuitously capture any logs from issued CI job run? I faced this issue ones but didn't think to save it. As it's suggested in #1323 it can happen due to unresolved promises so having some logs it will be easier to track issued one.

[nventuro]

Looks like #1526 will fix this - if it turns out it doesn't, we'll need to dig deeper.