Removes comments from CSS files with grunt
Changed gruntfile

Fixes #36 - added options to gruntfile in order to process SASS and
compress CSS file, concat JS files, then uglify JS files to compress
and remove comments.

Case study SCSS files must now be imported into screen.scss (section at
bottom).

When adding JS files, must add to the gruntfile directly (lines 128 &
132) - lib.js adds the libraries necessary for functions, scripts.js is
the individual case study page functionality.
Adding Rosetta Stone case study skeleton & CSS changes