Travis-CI: Do not fail build because of linter warnings
问题 I have an old python project that I am trying to progressively clean up using flake8 (to warn about PEP8 issues). I use Travis for continuous integration and want my build to fail if any unit test fails. However, I do not want my build to fail simply because flake8 produced a warning (e.g., about something minor like trailing white space). How do I configure Travis to output flake8 warnings (so that I can resolve them as I have time) without causing them to fail the build? My .travis.yml is