Docker and Travis are Linux only solutions
If you wonder to use Docker [1] or Travis CI [2] for build test or more advanced automation, note that these are Linux [3] only solutions and will not work with other operating systems such as FreeBSD [4]. You may want to take a look at old good Jenkins [5] for wider application possibilities :-)
[1] https://www.docker.com/
[2] https://travis-ci.org/
[3] https://www.linux.com/
[4] https://www.freebsd.org/
[5] https://jenkins.io/