The branch "topic/dnthayer/travis-ci" in the bro, broctl, bro-aux, btest, pysubnettree, and
trace-summary git repos adds a ".travis.yml" file, which is required in order to use Travis CI.
I have tested the ".travis.yml" files in each of the git repos and I've
seen all tests pass (sometimes there are tests in "bro" that fail,
but they seem to be race conditions rather than any specific
problem with running on Travis CI).