Fix target of less:production task
Make index.html the only entry point of the app

index.html file will be the entry point of the app, and it will be
copied under `/dev` or `/production` depending on the executed
build task.

So if you run `grunt dev`, you must point your browser to:

http://localhost:8000/dev/

And if you run `grunt production` you must point it to:

http://localhost:8000/production/

And your ready to be deployed app will be inside `/production` folder