Simple command-line adder function to practice docker

• Dockerize a program that takes 2 numbers via user CLI and returns the sum of those numbers.
• The program should be developed with tests using a simple CI/CD pipeline.

• clone repo to local machine.
• launch docker desktop.
• docker build --tag alexrkoch/docker-adder .
• docker run alexrkoch/docker-adder

• CircleCI: https://circleci.com/blog/build-cicd-piplines-using-docker/
• GitHub Actions described by Docker: https://docs.docker.com/language/python/configure-ci-cd/