minor, remove the unsupported oraclejdk7 in travis build
minor, remove the unsupported oraclejdk7 in travis build

apache/kylin,apache/kylin,apache/incubator-kylin,apache/incubator-kylin,apache/kylin,apache/incubator-kylin,apache/incubator-kylin,apache/incubator-kylin,apache/kylin,apache/kylin,apache/kylin,apache/incubator-kylin,apache/kylin