The build status of the project is "unknown" and the button links to an old repo name: https://travis-ci.org/arturadib/shelljs.
This seems to be a common bug with travis-ci (travis-ci/travis-ci#3264, travis-ci/travis-ci#1173, travis-ci/travis-ci#3264), but some people seem to have gotten positive results. travis-ci/travis-ci#3264 suggests pressing "sync" on travis-ci. Wanted to see if that might help.