investigate kafka messaging when necessary

[MrCreosote]

Messaging from ee2 -> kafka appears to fail silently in tests other than

WARNING  kafka.conn:conn.py:1532 DNS lookup failed for kafka:9092, exception was [Errno -2] Name or service not known. Is your advertised.listeners (called advertised.host.name before Kafka 9) correct and resolvable?

It similarly appears that docker kafka cannot be contacted from the local machine (unlike mongo, for example). Currently nothing is listening to the kafka feed, but before that happens we should figure out what's going on and ensure we have test coverage for successful and failing messages.

https://www.confluent.io/blog/kafka-client-cannot-connect-to-broker-on-aws-on-docker-etc/ might be useful.