If you have an project that is accepting code contributions then you will want to make sure that those well-meaning additions don’t break existing functionality. Services like GitHub allow you to review such pull requests via their colored diffs or even give instructions as to how to manually pull the commits into a local branch for evaluating this.
But there is a limit that is quickly being reached if you need to check all those pull requests manually. Even worse, this is a mundane task, usually trying out if the targets build and running the unit tests. Repetitive tasks like this are boring and thus nobody can be faulted for starting to neglect them.
In this blog post I will explain how to set up Travis-CI to have all pull requests be automatically checked for you. You will know for each pull request if merging it into your develop branch would break the build or unit tested functionality.