Create Dockerfile for local dev/testing

[chuckwondo]

Given that we have had difficulties with pinning specific Python dependencies that play nicely together in DPS, creating a Dockerfile based on the same Docker image that is specified in our algorithm_config.yaml file should help us identify and correct such problems early, prior to any attempt to register our algorithm, let alone attempt to run a job with it.

A relatively simple Dockerfile should suffice, and should likely need only to do the following:

• Use a FROM statement that specifies the same Docker image as specified in algorithm_config.yaml
• COPY the minimal set of files necessary to allow a subsequent RUN ./build.sh --dev to succeed

This can also serve as basis for later creating a devcontainer for use within VS Code, as well as for setting up a GitHub Action for running automated tests.