try out redpanda instead of kafka in pod

[tacaswell]

https://docs.redpanda.com/current/get-started/quick-start/

It looks like we can replace zookeeper + kafka with a single container (which would reduce some of the random startup issues) and get a web UI to look at them to boot.

We do use librdkafka based kafka bindings, but do not think we are using any of the fancy features.