Travis test keep failling saying this Loading "grunt-karma.js" tasks...ERROR TypeError: Cannot read property 'emit' of undefined

Question

Please we are facing a travis test on PR in the community-app. with the following error:

https://travis-ci.org/openMF/community-app/builds/230628985?utm_source=github_status&utm_medium=notification

please can someone give a hand? we have give some attemps like

npm install karma
npm install karma-grunt

to fixe it but none of them works.

Thanks,