Dockerfile and docker-compose.yaml to deploy container, and workflow to automatically build new images on master branch

[DavidHenryThoreau]

I've simplified the Dockerfile in order to reduce size, I've also create a docker-compose.yaml in order to deploy the container.
You can find in .github/workflow/docker.yaml a workflow to build docker images for arm64 and amd64.

[SamR1]

Hi,

Thanks for the PR.
It is replaced by the following PR #672.

I rebased the branch and made some changes and fix:

• for production, only fittrackee directory is required. And there's no need to install development dependencies.
• replace flask server with gunicorn (flask server is for development only)
• move environment variables in a .env file
• remove ports from docker-compose.yml for Redis and PostgreSQL containers
• add a container dedicated to workers (same image as the web application)
• add health checks
• publish image to Docker Hub in addition to Github registry. Docker images are built only on tag push (release workflow)