Move to using DSN, include header
Update method signatures, include headers
Add records, update constant name for password
Update comments, whitespace, logs and function specs
Add comments and remove logs
Add comments, reorder functions, consolidate exports
Clean up internal state management and functions

- Make all exchange methods talking to the worker a call instead of cast
- Keep track of AMQP connections by vhost and include which exchanges are using them
- Keep track of bindings as pgsql listen channels, allow for same channel to have multiple bindings
- Clean up add_binding, remove_binding, stop_exchange
- Start pgsql connection on exchange create
- Start AMQP connections on first binding to that vhost
- When validating exchange, only connect and disconnect to postgres, don't keep open or resuse anything