Preparing Kyuubi v0.4.0 release

Hi,

We are preparing to release Kyuubi v0.4.0, all tests and feedback are welcomed! Thanks!

Kyuubi v0.4.0 added some key features, such as,

KYUUBI-105 - Support High Availability with Failover Mode
KYUUBI-118 - Incremental Result Collection Support
KYUUBI-114 - Support to Run in Local Mode
KYUUBI-122 - obtain delegation tokens from possible kerberized services
KYUUBI-128 - LADP Authentication Support
and so on...

Also, v0.4.0 fixed a lot of issues, such as
KYUUBI-109 - add meaningful msg for front service port conflicts
KYUUBI-107 - kill yarn application fast when spark context fails to initialize
KYUUBI-133 - token expiration in HadoopRDD getPartitions
KYUUBI-108 - kyuubi server side direct memory oom
and so on...

Kyuubi v0.4.0 is automatically built against Apache Spark 2.1.3 by default, but it should work well with all Spark releases above 2.1.0 .

All helps are warm welcomed, thanks!

Best Regards

Kent