add vhost option

[ghost]

Hello!

Please add rabbitmq vhost selection. My variant in this request. If this variant is not good - please tell me why

[jasonmcintosh]

The command "./scripts/rabbitmq/rabbitmq-status.sh check_aliveness" exited with 1. Looks like tests are failing on this build. You fixed the api.py but didn't update the script which runs the check (which looks for a blank and sets it). Frankly, could probably remove that default from the shell script but I like keeping it there so people know they can easily override it. Default in the api.py then is probably unnecessary.