Fix deprecated '--join' option in the CoffeeScript 1.8.0

[see](https://github.com/jashkenas/coffeescript/commit/1cd48a9f5d38e823434c6c00ba41846270535a47)
seems to work
![untitled](https://cloud.githubusercontent.com/assets/47926/4099942/8970cf6c-3077-11e4-8deb-048fbc4e3318.png)