Module repositories are standard Git repositories. Generally, we want to protect the master branch and keep it from receiving direct commits. Contributors to component modules should instead submit pull requests to the repository and allow for a code review before accepting the code into the master branch. The master branch should be a functional version of the module at all times, although it need not be a version ready to be deployed into production. Treating the master as stable code allows non-production environments to point reliably at the master branch of all repositories, to get the latest accepted code during development. When it comes to deploying to production, we'll actually use a Git tag to create a version, such as 1.2.0. We can then deploy our latest code into non-production and formally accept code into production.