Implement an ability to configure worker options

[ellisv]

Things like worker worker_configuration_directory could also have been moved under worker_options configuration key but I wanted this pull request to be backwards compatible. If requested I could move those options there too.

[Phobetor]

Hi @ellisv

Thanks for your contribution!

Your change is released as part of version 2.0.0.

I moved the configuration option to

rabbit_mq_supervisor:
    consumer:
        general:
            worker:
                startsecs:              2       # supervisord worker option: seconds to consider program running
                autorestart:            true    # supervisord worker option: if supervisord should restarted program automatically
                stopsignal:             INT     # supervisord worker option: the signal used to kill the program
                stopasgroup:            true    # supervisord worker option: if whole process group should be stopped
                stopwaitsecs:           60      # supervisord worker option: seconds to wait after stop signal before sending kill signal

as there are some other new options that also fit there.