Chores

-Refactoring of SCSS, new mixins and variables
- Flash messages color coded, show up in top left corner
- Users index table shows 'patron' for users with no other role
- Users form is clearer, as 'role' section has a label
- Search results display more clearly, have adorable icon, 'search again' box removed
- 'Manage Users' big icon link shows up in left column for librarians/admins
- 3 new buttons styles- 'go', 'meh', and 'danger'- applied liberally throughout so action items are much clearer

@eak000 Can you take a look at this and give feedback on my styling changes?