svn merge -c 1467090 FIXES: HADOOP-9233. Cover package org.apache.hadoop.io.compress.zlib with unit tests. Contributed by Vadim Bondarev


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23@1467102 13f79535-47bb-0310-9956-ffa450edef68