Stubs out managment API calls

Fixes #53 

**Pull request for discussion, not ready for merge.*

Discovery of RabbitMQ Management API has resulted in a refactoring of the types of health checks the module can report on the status of the larger Message Broker / RabbitMQ system.

Reference:
http://hg.rabbitmq.com/rabbitmq-management/raw-file/rabbitmq_v3_3_5/priv/www/api/index.html