See: METRON-1274 <https://issues.apache.org/jira/browse/METRON-1274> and https://travis-ci.org/apache/metron/builds
An example failure is https://travis-ci.org/apache/metron/builds/290806887 This is possibly intermittent and possibly a result of METRON-1241 <https://issues.apache.org/jira/browse/METRON-1241>, but it hasn't been dug into yet. More details are in the ticket. Please refrain from merging PRs into master until this is resolved. Thanks, Justin
