Wait until daemon dies

- wait daemon process until they stopped
    - rake daemon:stop waits until three sub-processes (job_worker, analyzer_worker, service_worker) have stopped.
    - The timeout is set to 30 sec.
    - If these process do not stop after 30 secs, kill -9 are sent to these.
        - If the Daemon.spawn! method receives opts having `:timeout`, stop command is wait until the process is stopped.
- Start and stop of daemons are executed in parallel in order to shorten the time to stop.