Expose new cmdline options that are passed to rabbitmqadmin

* add --rmquser used to override default user used to connect to RMQ (guest)
* add --rmqpass used to override default pass used to connect to RMQ (guest)
* add --rmqhost used to override default host for RMQ server (127.0.0.1)
* add --rmqport used to override default port for RMQ server (15672)