Add Dockerfile for auto image build on docker hub
Add Dockerfile for auto image build on docker hub

The Dockerfile needs both maven for building and tomcat for running. Ideally we
would change this to build on Travis using spotify's docker pom plugin and push
the resulting image to docker hub. That would make the image a lot smaller.

zhx828/oncokb,oncokb/oncokb,oncokb/oncokb,oncokb/oncokb,zhx828/oncokb,zhx828/oncokb