YARN-1748. Excluded core-site.xml from hadoop-yarn-server-tests package's jar and thus avoid breaking downstream tests. Contributed by Sravya Tirukkovalur.
svn merge --ignore-ancestry -c 1573795 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.4@1573797 13f79535-47bb-0310-9956-ffa450edef68