Multiple logstash plugins failing on travis

We have many plugins failing against logstash-core, this must be fixed..Below is a sample (small portion) of the ones failing (full list in https://travis-ci.org/logstash-plugins/):

- [ ] [logstash-codec-protobuf](https://github.com/logstash-plugins/logstash-codec-protobuf) [](https://travis-ci.org/logstash-plugins/logstash-codec-protobuf)
- [ ] [logstash-codec-compress_spooler](https://github.com/logstash-plugins/logstash-codec-compress_spooler) [](https://travis-ci.org/logstash-plugins/logstash-codec-compress_spooler)
- [ ] [logstash-codec-csv](https://github.com/logstash-plugins/logstash-codec-csv) [](https://travis-ci.org/logstash-plugins/logstash-codec-csv)
- [ ] [logstash-codec-example](https://github.com/logstash-plugins/logstash-codec-example) [](https://travis-ci.org/logstash-plugins/logstash-codec-example)
- [ ] [logstash-codec-json_pretty](https://github.com/logstash-plugins/logstash-codec-json_pretty) [](https://travis-ci.org/logstash-plugins/logstash-codec-json_pretty)
- [ ] [logstash-codec-oldlogstashjson](https://github.com/logstash-plugins/logstash-codec-oldlogstashjson) [](https://travis-ci.org/logstash-plugins/logstash-codec-oldlogstashjson)
- [ ] [logstash-codec-protobuf](https://github.com/logstash-plugins/logstash-codec-protobuf) [](https://travis-ci.org/logstash-plugins/logstash-codec-protobuf)
- [x] [logstash-codec-s3plain](https://github.com/logstash-plugins/logstash-codec-s3plain) [](https://travis-ci.org/logstash-plugins/logstash-codec-s3plain)
- [ ] [logstash-codec-sflow](https://github.com/logstash-plugins/logstash-codec-sflow) [](https://travis-ci.org/logstash-plugins/logstash-codec-sflow)
- [ ] [logstash-filter-age](https://github.com/logstash-plugins/logstash-filter-age) [](https://travis-ci.org/logstash-plugins/logstash-filter-age)
- [ ] [logstash-filter-alter](https://github.com/logstash-plugins/logstash-filter-alter) [](https://travis-ci.org/logstash-plugins/logstash-filter-alter)
- [ ] [logstash-filter-bytesize](https://github.com/logstash-plugins/logstash-filter-bytesize) [](https://travis-ci.org/logstash-plugins/logstash-filter-bytesize)
- [ ] [logstash-filter-cipher](https://github.com/logstash-plugins/logstash-filter-cipher) [](https://travis-ci.org/logstash-plugins/logstash-filter-cipher)
- [ ] [logstash-filter-cloudfoundry](https://github.com/logstash-plugins/logstash-filter-cloudfoundry) [](https://travis-ci.org/logstash-plugins/logstash-filter-cloudfoundry)
- [ ] [logstash-filter-collate](https://github.com/logstash-plugins/logstash-filter-collate) [](https://travis-ci.org/logstash-plugins/logstash-filter-collate)
- [x] [logstash-filter-date](https://github.com/logstash-plugins/logstash-filter-date) [](https://travis-ci.org/logstash-plugins/logstash-filter-date) https://github.com/logstash-plugins/logstash-filter-date/pull/117
- [ ] [logstash-filter-debug](https://github.com/logstash-plugins/logstash-filter-debug) [](https://travis-ci.org/logstash-plugins/logstash-filter-debug)
- [ ] [logstash-filter-emoji](https://github.com/logstash-plugins/logstash-filter-emoji) [](https://travis-ci.org/logstash-plugins/logstash-filter-emoji)
- [ ] [logstash-filter-jdbc_static](https://github.com/logstash-plugins/logstash-filter-jdbc_static) [](https://travis-ci.org/logstash-plugins/logstash-filter-jdbc_static)
- [ ] [logstash-filter-jdbc_streaming](https://github.com/logstash-plugins/logstash-filter-jdbc_streaming) [](https://travis-ci.org/logstash-plugins/logstash-filter-jdbc_streaming)
- [ ] [logstash-filter-kubernetes_metadata](https://github.com/logstash-plugins/logstash-filter-kubernetes_metadata) [](https://travis-ci.org/logstash-plugins/logstash-filter-kubernetes_metadata)
- [ ] [logstash-filter-language](https://github.com/logstash-plugins/logstash-filter-language) [](https://travis-ci.org/logstash-plugins/logstash-filter-language)
- [ ] [logstash-filter-lookup](https://github.com/logstash-plugins/logstash-filter-lookup) [](https://travis-ci.org/logstash-plugins/logstash-filter-lookup)
- [ ] [logstash-filter-math](https://github.com/logstash-plugins/logstash-filter-math) [](https://travis-ci.org/logstash-plugins/logstash-filter-math)
- [ ] [logstash-filter-metaevent](https://github.com/logstash-plugins/logstash-filter-metaevent) [](https://travis-ci.org/logstash-plugins/logstash-filter-metaevent)
- [ ] [logstash-filter-punct](https://github.com/logstash-plugins/logstash-filter-punct) [](https://travis-ci.org/logstash-plugins/logstash-filter-punct)
- [ ] [logstash-filter-range](https://github.com/logstash-plugins/logstash-filter-range) [](https://travis-ci.org/logstash-plugins/logstash-filter-range)
- [x] [logstash-filter-script](https://github.com/logstash-plugins/logstash-filter-script) [](https://travis-ci.org/logstash-plugins/logstash-filter-script)
- [x] [logstash-filter-unique](https://github.com/logstash-plugins/logstash-filter-unique) [](https://travis-ci.org/logstash-plugins/logstash-filter-unique)
- [ ] [logstash-filter-yaml](https://github.com/logstash-plugins/logstash-filter-yaml) [](https://travis-ci.org/logstash-plugins/logstash-filter-yaml)
- [ ] [logstash-filter-zeromq](https://github.com/logstash-plugins/logstash-filter-zeromq) [](https://travis-ci.org/logstash-plugins/logstash-filter-zeromq)
- [x] [logstash-input-beats](https://github.com/logstash-plugins/logstash-input-beats) [](https://travis-ci.org/logstash-plugins/logstash-input-beats)
- [ ] [logstash-input-cloudwatch_logs](https://github.com/logstash-plugins/logstash-input-cloudwatch_logs) [](https://travis-ci.org/logstash-plugins/logstash-input-cloudwatch_logs)
- [ ] [logstash-input-drupal_dblog](https://github.com/logstash-plugins/logstash-input-drupal_dblog) [](https://travis-ci.org/logstash-plugins/logstash-input-drupal_dblog)
- [ ] [logstash-input-dynamodb](https://github.com/logstash-plugins/logstash-input-dynamodb) [](https://travis-ci.org/logstash-plugins/logstash-input-dynamodb)
- [ ] [logstash-input-file](https://github.com/logstash-plugins/logstash-input-file) [](https://travis-ci.org/logstash-plugins/logstash-input-file)
- [ ] [logstash-input-fluentd](https://github.com/logstash-plugins/logstash-input-fluentd) [](https://travis-ci.org/logstash-plugins/logstash-input-fluentd)
- [ ] [logstash-input-gemfire](https://github.com/logstash-plugins/logstash-input-gemfire) [](https://travis-ci.org/logstash-plugins/logstash-input-gemfire)
- [ ] [logstash-input-generator](https://github.com/logstash-plugins/logstash-input-generator) [](https://travis-ci.org/logstash-plugins/logstash-input-generator)
- [ ] [logstash-input-googleanalytics](https://github.com/logstash-plugins/logstash-input-googleanalytics) [](https://travis-ci.org/logstash-plugins/logstash-input-googleanalytics)
- [ ] [logstash-input-graphite](https://github.com/logstash-plugins/logstash-input-graphite) [](https://travis-ci.org/logstash-plugins/logstash-input-graphite)
- [ ] [logstash-input-http_poller](https://github.com/logstash-plugins/logstash-input-http_poller) [](https://travis-ci.org/logstash-plugins/logstash-input-http_poller)
- [ ] [logstash-input-jmx-pipe](https://github.com/logstash-plugins/logstash-input-jmx-pipe) [](https://travis-ci.org/logstash-plugins/logstash-input-jmx-pipe)
- [ ] [logstash-input-journald](https://github.com/logstash-plugins/logstash-input-journald) [](https://travis-ci.org/logstash-plugins/logstash-input-journald)
- [ ] [logstash-input-kafka](https://github.com/logstash-plugins/logstash-input-kafka) [](https://travis-ci.org/logstash-plugins/logstash-input-kafka)
- [ ] [logstash-input-log4j2](https://github.com/logstash-plugins/logstash-input-log4j2) [](https://travis-ci.org/logstash-plugins/logstash-input-log4j2)
- [ ] [logstash-input-mongodb](https://github.com/logstash-plugins/logstash-input-mongodb) [](https://travis-ci.org/logstash-plugins/logstash-input-mongodb)
- [ ] [logstash-input-neo4j](https://github.com/logstash-plugins/logstash-input-neo4j) [](https://travis-ci.org/logstash-plugins/logstash-input-neo4j)
- [ ] [logstash-input-netflow](https://github.com/logstash-plugins/logstash-input-netflow) [](https://travis-ci.org/logstash-plugins/logstash-input-netflow)
- [ ] [logstash-input-perfmon](https://github.com/logstash-plugins/logstash-input-perfmon) [](https://travis-ci.org/logstash-plugins/logstash-input-perfmon)
- [ ] [logstash-input-pipe](https://github.com/logstash-plugins/logstash-input-pipe) [](https://travis-ci.org/logstash-plugins/logstash-input-pipe)
- [ ] [logstash-input-relp](https://github.com/logstash-plugins/logstash-input-relp) [](https://travis-ci.org/logstash-plugins/logstash-input-relp)
- [x] [logstash-input-s3](https://github.com/logstash-plugins/logstash-input-s3) [](https://travis-ci.org/logstash-plugins/logstash-input-s3)
- [ ] [logstash-input-salesforce](https://github.com/logstash-plugins/logstash-input-salesforce) [](https://travis-ci.org/logstash-plugins/logstash-input-salesforce)
- [x] [logstash-input-tcp](https://github.com/logstash-plugins/logstash-input-tcp) [](https://travis-ci.org/logstash-plugins/logstash-input-tcp)https://github.com/logstash-plugins/logstash-input-tcp/pull/102
- [ ] [logstash-input-unix](https://github.com/logstash-plugins/logstash-input-unix) [](https://travis-ci.org/logstash-plugins/logstash-input-unix)
- [ ] [logstash-input-zenoss](https://github.com/logstash-plugins/logstash-input-zenoss) [](https://travis-ci.org/logstash-plugins/logstash-input-zenoss)
- [ ] [logstash-input-zeromq](https://github.com/logstash-plugins/logstash-input-zeromq) [](https://travis-ci.org/logstash-plugins/logstash-input-zeromq)
- [ ] [logstash-integration-elasticsearch](https://github.com/logstash-plugins/logstash-integration-elasticsearch) [](https://travis-ci.org/logstash-plugins/logstash-integration-elasticsearch)
- [ ] [logstash-integration-zeromq](https://github.com/logstash-plugins/logstash-integration-zeromq) [](https://travis-ci.org/logstash-plugins/logstash-integration-zeromq)
- [ ] [logstash-mixin-aws](https://github.com/logstash-plugins/logstash-mixin-aws) [](https://travis-ci.org/logstash-plugins/logstash-mixin-aws)
- [ ] [logstash-mixin-http_client](https://github.com/logstash-plugins/logstash-mixin-http_client) [](https://travis-ci.org/logstash-plugins/logstash-mixin-http_client)
- [x] [logstash-mixin-rabbitmq_connection](https://github.com/logstash-plugins/logstash-mixin-rabbitmq_connection) [](https://travis-ci.org/logstash-plugins/logstash-mixin-rabbitmq_connection) https://github.com/logstash-plugins/logstash-mixin-rabbitmq_connection/pull/46
- [x] [logstash-mixin-zeromq](https://github.com/logstash-plugins/logstash-mixin-zeromq) [](https://travis-ci.org/logstash-plugins/logstash-mixin-zeromq) https://github.com/logstash-plugins/logstash-mixin-zeromq/pull/10