http://tenderlovemaking.com/2015/02/13/predicting-test-failues.html
blog-post-predicting-test-failures#let-ci-run-unrelated-tests1 But what if we could predict which tests are likely to fail after we've changed the code? If we run just those tests, then we could send a pull request and let Travis run the thousands of unrelated tests in the whole suite. blog-post-predicting-test-failures#let-ci-run-unrelated-tests1