Docker build and image to simplify setup of pipeline

[hldnova]

Problem description
Users want to demonstrate the pipeline: Apache access logs -> Logstash with Pravega output plugin -> Pravega stream. It is non-trivial for them to set up ruby build environment to build the plugin, install and setup logstash, install/configure logstash output plugin for pravega.

Problem location

Suggestions for an improvement
I Use docker image to simplify the setup of pipeline including installation/configuration of pravega, logstash, the plugin, and logstash filters.