[BACKLOG-115] Certify support for Kerberos for CDH 5.1

Support MR2 jobs for CDH51 shim (PDI-11959)
[BACKLOG-751] CLONE - Hadoop Job Executor: Jobs using org.apache.hadoop.mapreduce API don't work - Fix for CDH 5.1
Merge pull request #158 from stepanovdg/BACKLOG-751

[BACKLOG-751]CLONE - Hadoop Job Executor: Jobs using org.apache.hadoop.mapreduce API don't work - Fix for CDH 5.1