travis - silent build fails; gulp-nsp in prepublish

[gruppjo]

Example: https://travis-ci.org/mwaylabs/generator-m-ionic/jobs/195803339#L1194
Problem with plumber? https://www.npmjs.com/package/gulp-plumber
Problem with coveralls? https://coveralls.io/
Problem with env.CI and Travis?
Problem with setup (not using npm test)? https://docs.travis-ci.com/user/languages/javascript-with-nodejs
Same problem for demo project? https://github.com/mwaylabs/generator-m-ionic-demo

• use "scripts": { "test" } in package.json from now on instead of after_scripts in .travis.yml
• use generator-generator setup? gulp-nsp
  • https://github.com/yeoman/generator-generator/blob/master/package.json#L20
  • https://github.com/yeoman/generator-generator/blob/master/gulpfile.js