CI Updates (#3)

# Added
- Deployment step in CI
- Initial commit of Docker, CI build, and configuration
- Move `certbot` directory from `moodle-docker` to this repo
- CONTRIBUTION.md

 # Changed
- Clean up CI configuration
- Update scripts
  - tag checking
  - docker publish

Certbot initial commits (#1)

- Add certbot container for manage TLS certificates
- Adds a docker volume shared with the nginx container for
retrieving TLS certificates
- Add README, CHANGELOG
- Add build scripts and setup Travis-CI builds

Initial commit