Fixes event_fired / event_failed only looking at public methods

Sometimes it's more convenient to implement these methods as protected /
private for records to hide them from the public API. Since we're using
send we should be looking at protected / private methods as well.

On Ruby 2.x this is worse because responds_to? returns false for
protected methods.
Merge pull request #125 from darkside/feature/fix-event-fired-failed-responds-to

Fixes event_fired / event_failed only looking at public methods