Describe the solution you'd like
Currently, the consumer group rebalance will error out if a topic does not exist. Official Kafka clients (librdkafka, java) do not throw an error in this case. Instead, they hand back empty assignments to all the consumers. If the topic comes into existence later, then a rebalance is initiated.

It would be great if kafka-go had the same behavior. See background and discussion in #200 and #229