Add Dockerfile to create Docker image
Add Dockerfile to create Docker image

This change commits a Dockerfile to create an image for the Joshua
decoder.

thammegowda/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,fhieber/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,fhieber/incubator-joshua,thammegowda/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,thammegowda/incubator-joshua,thammegowda/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,fhieber/incubator-joshua,fhieber/incubator-joshua,thammegowda/incubator-joshua