Add SQL support

Apache Gearpump is a real-time big data streaming engine. It is inspired by recent advances in the Akka framework and a desire to improve on existing streaming frameworks. Gearpump is event/message based and featured as low latency handling, high performance, exactly once semantics, dynamic topology update, Apache Storm compatibility, etc. This project is about building a SQL layer with Apache Calcite to help those who are unfamiliar with Scala/Java to use Gearpump.