At the time i write this, I have a PR that builds and pass the tests correctly. The problem is sometimes, after rebasing with changes in master branch, TravisCI builds fails because a bad environment, but after some commit recreations, it passes the tests.
After studying some of that builds, I think the problem is that installing some things from scratch has a performance impact and other issues like unavailable services or bad packages installations.
A possible great solution is creating a base image that contains some of the software preinstalled (e.g, databases or messages queues) as the environment for testing is the same for every build.
This can be related to an old task (
AIRFLOW-87) about creating a development environment.