Add build-distro task

The task should create a zip with war and all modules as well as a docker config for running distro.

The docker config should include 3 containers:
1) JDK 1.7.x (or 1.8.x for OpenMRS Platform 2.x) + Tomcat 7.x + OpenMRS distro as configured in distro properties (start from tomcat:7 image)
2) MySQL 5.6.x (simply use default mysql:5.6 image)
3) Volume container for MySQL (see how it can be created at

All 3 containers should be wired together with docker-compose.

To start with see existing configs e.g. https://github.com/psbrandt/openmrs-platform-docker