Create Dockerfile

[monorkin]

Hi!

First off, ❤️ the project. Though it was a bit hard to figure out how to set it up. The readme could use some work (E.g. that you must use Coinbase's V1 API and what the webhook password is used for).

I created a docker file for this project so that it can be run with Docker. It assumes that the configuration file is named production.yml since I saw that was what you used in the .gitignore file.

I would love to see this project on hub.docker.com!