`Completed` event missed for short-running task about taskee HOT 1 CLOSED

This happened because a newly instantiated task will always register a Created event, regardless of its state.

To handle this, we could:

1. Add some logic to only register the most recent event for each task (in the example above, ignore the Created event and register the Completed event.)
2. Redesign the event system to allow tasks to store an event queue.

Option 1 could technically miss a notification in the unlikely case that someone is watching for Created events but not Completed events. Option 2 adds a bit more complexity to cover a relatively minor corner case, and also raises the question of whether we send multiple notifications for a single task or need to make a new system to combine notifications.

I think the path forward may be clearer once I tackle #13.

from taskee.