Update hs2 client API to the version hive uses in 5.1.

The driving motivation is to be able to return precision/scale for
decimal types.

Change-Id: I1b49c5a61b59a292bc09612c7945191078a22bf8
Reviewed-on: http://gerrit.sjc.cloudera.com:8080/3772
Reviewed-by: Nong Li <nong@cloudera.com>
Tested-by: jenkins