Getting started with automated testing workflow and CI on Ruby

If you have been writing Ruby / Rails code for a while, but still can’t grasp on the ‘why’ to write automated test, (eg. why do so many Ruby dev job posting requires automated test skill like Rspec, minitest etc? How does writing automated test makes me a better developer or help the company I work with? )or if you are not sure on how the CI (continuous integration) stuff works, this article is written to address these questions!.