Add a continuous deployment demonstrator

Similar to our jenkins setup internally and kinda like this https://mesosphere.com/blog/2015/04/02/continuous-deployment-with-mesos-marathon-docker

We should probably create a simple demonstrator github repo - and spin out the other necessary bits in AWS. Maybe we could use a cloud CI (e.g. wercker / travis / circleCI / drone.io / or something similar so we don't have to do the jenkins heavy lifting).
If we hooked this up to quay.io for the docker registry then we could build / push from the cloud CI to quay.io and trigger a deployment to marathon.

Wercker supports deployments - maybe we could write a custom deployment step for that to deploy into AWS (needs more investigation)