Add RabbitMQ

[jrwdunham]

Problem: We have a Clojure HTTP API, a postgres DB, and a ClojureScript UI, but we have no practical infrastructure for processing requests asynchronously. Add RabbitMQ.

A/C:

• Add basic RabbitMQ functionality to DativeBase.
• Add Docker config and docs for installing RabbitMQ and setting up a local topology
• Add an API endpoint that receives HTTP requests, enqueues a message, and returns an appropriate "async processing initiated" HTTP response.
• Ensure there is a handler for processing the Rabbit message.
• Get RabbitMQ running on CIPL server and ensure all of the above works on the test server.