Compiling storefront sass with bourbon and susy included

Hello,

Ive downloaded the Koala app on my macbook to compile the storefront sass file to css but i get an error message:

”Error: File to import not found or unreadable: bourbon.”

i guess it isn’t able to include Susy as well, how do i install / import these files?

I’ve been searching the web a while now and still havent found an answer