Continuous integration with Travis CI

It is often the case in large software systems that for every change to our code, we want both our unit and integration tests to run automatically. Moreover, in a collaborative project, the manual way is just not practical. Fortunately, Continuous Integration is a practice that aims to automate those aspects of software development. Travis CI is a public continuous integration service that allows you to run your project's tests automatically in the cloud, based on event hooks. One example of an event hook is when new commits are pushed.

Travis is generally used to automate running builds and tests and to report failed builds, but can also be used for creating releases and even deploying them in staging or production environments. We'll focus on one aspect of Travis in this section, performing automated runs of our tests for our project. GitHub already has integration with Travis that can run tests for new commits in our project. To make this happen, we...