CircleCI job to test docker-compose files (both development & DO 1Click)

[iainsproat]

We are currently missing any tests for the deployment of speckle-server to Docker Compose.
Due to the missing tests we have on occasion broken Digital Ocean 1-click deployment and our local dev environments.

CircleCI can deploy a VM runner with docker compose installed.
We will need to load the Docker images created in the workspace, and this may require some templating of the docker compose files.
We may also need to set up /etc/hosts (e.g. 127.0.0.1 speckle.internal) and configure the environment variable to use that alias as its domain.