citra-emu/citra — pull request #319 by yuriks (2014-12-20 16:38:29+00:00)
Title: Travis: Enable APT cache. This should give us a small boost

http://docs.travis-ci.com/user/caching/#Caching-Ubuntu-packages

Unfortunately I don't think there's anything similar for brew. I'll try looking into using the local filesystem cache for that instead, however.