Dockerise Application

[MattTennison]

To improve developer experience, we can dockerise this application to make it easier to build and run locally. If combined with a docker-compose file, we could make it really easy to get a end to end environment up and running on a developers machine.

This will also make it easier for us to setup end to end test environments, as we can use services that run docker images for us to deploy it. For example - https://dokku.com/ is a PaaS that we can install on a single host, and run multiple applications side-by-side.