github/linguist — pull request #1931 by aroben (2014-12-31 15:58:26+00:00)
Title: Opt in to container-based Travis CI builds

This speeds up our builds by providing lower latency, better caching, and more resources on the build machine. See http://docs.travis-ci.com/user/workers/container-based-infrastructure/.

The only major change here is that we can't install `libicu-dev` globally on the test machine. Instead we extract it to `vendor/debs` and point `charlock_holmes` at it.

Note that the build sometimes fails because apparently the `ace_modes.json` file sometimes can't be downloaded. This would normally cause us to skip the test that relies on that file, but `#skip` doesn't exist in the version of `test-unit` being used on Ruby 2.2. #1930 will fix the `#skip` problem. I doubt that the intermittent failure to download `ace_modes.json` is unique to container-based builds, though I suppose it's possible.

/cc @arfon @bkeepers