Merge pull request #1362 from MITx/feature/edz/revert-explicit-charset

Feature/edz/revert explicit charset

lms/static/sass/application.scss

-@charset "UTF-8";
 @import 'bourbon/bourbon';
 
 @import 'base/reset';

lms/static/sass/course.scss

-@charset "UTF-8";
 @import 'bourbon/bourbon';
 
 @import 'base/reset';

lms/static/sass/ie.scss

-@charset "UTF-8";
 @import "bourbon/bourbon";
 @import "base/variables";