Testing is important - most people understand that by now. A lot of people write tests for their open source code already, but in-house testing is still hard. [...] While I prefer to run my database tests against a SQLite in memory database, there are these edge cases, where I work with multiple database or I write a direct query (and by-pass the ORM-magic). In these cases I need to have that database server available in my test environment! The following blog posts explains how to solve these things with Travis-CI. I will walk you through the setup on Travis-CI's business service. But most of this applies to their open source offering as well.
He's broken it up into a few different steps - the setup and configuration of the ".travis.yml" file, adding in a "composer.json" file with the needed dependencies and the recommendation of a "phpunit.xml" in your project's root. He shows how to use Doctrine's "SchemaTool" utility to generate his schema off of the comments on his entities (instead of checking in SQL). This setup them gives him access to Doctrine's EntityManager object in his tests and he can go from there. If you're thinking about doing something similar, check Travis' list of supported databases before you do anything, just to be sure.