YARN-1450. Fixed test failure in TestUnmanagedAMLauncher by removing its dependency on distributed-shell. Contributed by Binglin Chang.
svn merge --ignore-ancestry -c 1548619 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1548622 13f79535-47bb-0310-9956-ffa450edef68