getDeltas should be encapsulated. It looks like it was public for the sake
of the tests, and its behavior can be inferred by looking at the result of
processing.
Move create config functions out of the main delta-processor.ts file. Change some any types to more specific types. Define document structure better. Move prometheus logic out of processor class. Do not call logger directly, listen for events and log them. Change logger to more PSR-3 compliant style. Extract amqp connection into its own class. Create avro and mongo objects in factory.