Flaky test: TestRocksDbKeyValueStore suite

:samza-kv-rocksdb_2.11:testPicked up _JAVA_OPTIONS: -Xmx2048m -Xms512m
testFlush FAILED
    org.apache.samza.SamzaException: Error opening RocksDB store dbStore at location /tmp, received the following exception from RocksDB org.rocksdb.RocksDBException: "
        at org.apache.samza.storage.kv.RocksDbKeyValueStore$.openDB(RocksDbKeyValueStore.scala:99)
        at org.apache.samza.storage.kv.TestRocksDbKeyValueStore.testFlush(TestRocksDbKeyValueStore.scala:73)
5 tests completed, 1 failed
:samza-kv-rocksdb_2.11:test FAILED