Hand-edit package-lock.json to revert the event-stream version to 3.3.4
Hand-edit package-lock.json to revert the event-stream version to 3.3.4

This therefore removes the bad flatmap-stream package.

mozilla-services/screenshots,mozilla-services/pageshot,mozilla-services/pageshot,mozilla-services/screenshots,mozilla-services/screenshots,mozilla-services/pageshot,mozilla-services/screenshots,mozilla-services/pageshot