Rpm spec

Simple RPM spec to construct a RPM out of kafkacat. It requires the RPMP provided in librdkafka. For future reference for RPM builders, this is the trick to build a tar.gz

git archive --format=tar.gz --prefix=kafkacat-1.1.0/ 1.1.0 > ~/kafkacat-1.1.0.tar.gz
re count behaviour:   stats.tx is the number of messages produced by kafkacat, it doesn't know what has actually been sent to the broker. But it is mainly used to limit the number of messages on the kafkacat side, failures are a later problem.
Updating that counter in a dr_cb wont work since then too many messages will most likely be produced.