Set a default priority for reporters.

They should be the last service in the event cycle to get called.
To override this, just extend the class and set the constant to the value you want.
Generalize exceptions for the HealthCheck service.
Split exceptions into appropriate type(s).

ErrorExceptions handle exceptions thrown on behalf of error(s).
The original HealthCheckException can be used by tests or other services to indicate related problems.
Catch only HealthCheck related exceptions.
Create a subscriber for trapping error(s) during tests.