Setting up CI with CircleCI
There is a reasonably extensive landscape when it comes to hosted CI systems. If you add in self-hosted systems, the list grows even longer. Tools such as Jenkins have been around for many years, initially as self-hosted systems. Inevitably, hosted versions of tools such as Jenkins have emerged from various companies. In this section, we'll walk through the steps of setting up CircleCI (https://circleci.com) to run our unit tests and produce a code coverage report on every code commit.
Note
Since this is a book about serverless patterns, I'll encourage you to pick whatever tool works for your purposes with a very strong lean towards hosted CI/CD system. Using a hosted CI/CD systems means that you can focus more on your application code rather than the CI/CD system, which is just a tool we need to get our jobs done.
Setting up a brand new project with CircleCI is quite simple, and it has easy integration with both GitHub and Bitbucket. The first thing you'll need...