I would store components source in GitHub and use NPM for publishing/distributing releases.

Here's my checklist for maintaining components:

• Add Unit tests
• Add Code Coverage
• Use a CI tool (TravisCI/CircleCI) that runs these tests and reports them back to github (pr/branch status, badges)
• Maintain a Changelog (this can be autogenerated via commit message syntax)
• Use Build scripts (ex: transpile via babel, bump npm version, publish to npm)