Use vilein-0.2.0
Wait serf for ready
Support #ready? and #wait_for_ready
Filter event to handle by Agent.new(events_only:)
Re-design event names

before: "mamiya-{event_name}"
after:  "mamiya:{event_name}"
        "mamiya:{event_name}:{action}"
calls another method when action specified
Mamiya::Agent#distribute to send fetch requests

- Mamiya::Agent#trigger to trigger any events