Hello 😄

I'm opening this issue because @sindresorhus pointed me here after a long conversation on twitter. Essentially, I wanted to mimic some function that exists in np. I've made a demo repo here https://github.com/Aghassi/promise-observables

Essentially, if you run node transpiled.js, you will see UnhandledPromiseWarning on failure. I've tried a number of things to catch properly, but have been unsuccessful. Could it have something to do with how this repo rejects promises? I wanted to get the discussion going before I was able to possibily contribute because of other priorities I have running at the moment.