The code is the main part that changes during model development. Copying the code to the Docker image before installing the dependencies prevents caching of the dependencies since all Docker layers need to be rebuilt if a previous one changes.
This PR changes the order of the Docker file to copy the code as the last step so that dependencies only need to be reinstalled if the requirements.txt file changes. This speeds up local build times by a large amount since dependencies don't need to be reinstalled on every code change.