How to tell travis that test is failed?
The test-run is outputting XML and reporting success on the generation, which is useful for Jenkins, but not Travis CI.

drush test-run --xml 'Andy Truong'


Change that to

drush test-run 'Andy Truong'


And you should be set.

For reference, see https://drupal.org/project/travis_ci_drupal_module_example and https://travis-ci.org/sonnym/travis-ci-drupal-module-example