Heroku gulp deployment

Question

I read the whole topic about gulp and heroku, but I don't understand what happened to my procfile.

When I'm in local startup, how does it work: node node_modules / gulp / bin / gulp build

So in procfile I write: web: node node_modules / gulp / bin / gulp build

as stated here http://www.sitepoint.com/deploying-heroku-using-gulp-node-git/

But still this does not work. There is no design problem with heroku magazine ...

Any idea?