Added generated assets folder.
Merge branch 'master' of https://github.com/web-cat/code-workout
Add UploadRoster model and controller from Pythy
Make UploadedRoster work with columns for first name, last name, and user roles
Add UploadRoster view, from pythy's
Add require Bootstrap to fix non-appearing modals
Exercises have optional titles in db, display title X123: Title or First Tag