WIP: pipe all scripts into file

Many Travis failures are just “no output” and I have no idea what it is.
For instance:
https://travis-ci.org/vojtajina/angular.js/builds/26618490
https://travis-ci.org/vojtajina/angular.js/builds/26622078
https://staging.travis-ci.org/vojtajina/angular.js/builds/391690
https://staging.travis-ci.org/vojtajina/angular.js/jobs/391693

We had an issue before, when `npm install` produced some weird character that killed streaming of the output. This would work around such an issue.

That said, I don’t expect this to be the issue as if it was, the build would actually run - just not stream the output to the web interface. Based on logs from BrowserStack, that was not the case.