Description
Since Scala 2.12 requires Java 8 while Kafka still supports Java 7, the *All commands don't include Scala 2.12. As such, simply running releaseTarGzAll won't generate the Scala 2.12 artifacts and we also need to run `./gradlew releaseTagGz -PscalaVersion=2.12`.
The following page needs to be updated to include this and any other change required:
https://cwiki.apache.org/confluence/display/KAFKA/Release+Process