Adding a dockerfile and docker-compose.yaml

[aevo98765]

Hello, when we first started using minerva-author we found the requirements to run difficult between our team. In addition to this we potentially wanted to productionize this for our own use. Therefore to fulfil these two requirements we created a Dockerfile and docker-compose.yaml. We would like to contribute these to your project if you would be interested?
Tasks:

• Add a Dockerfile
• Add a docker-compose file
• Amend README to allow users to use Minerva Author via Docker.

[aevo98765]

Pull request: #42