Errors should fail on GitHub Actions

[AntoineAugusti]

When the script has an error, it should fail

https://github.com/cds-snc/notification-api/runs/1381429350

Run cds-snc/notification-pr-bot@master
(node:5715) UnhandledPromiseRejectionWarning: HttpError: Not Found

But the step is marked as ✅