Sensu-go: Check TTL events can be created even if failing keepalive events exist

[echlebek]

Expected Behavior

An entity with a keepalive failure event should not create a check TTL event.

Current Behavior

Failing events are created for both keepalives and checks.

Possible Solution

When a check TTL event fails to fire, the handler should consult the store for whether or not a failing keepalive event exists for the entity in question.

Steps to Reproduce (for bugs)

1. Create a check with TTL enabled.
2. Take the associated entity offline.
3. Observe failing events for both the keepalive and check.

Context

Reported by steveberryman in the community slack.

[calebhailey]

It this getting released with 5.17.0?

[palourde]

Yep, it has been included in 5.17 but it wasn't merged right away in master so Github didn't closed it automatically 🤦‍♂