Removing the crud.rb containing exercice answers
Fixing AR exercices
Fixing header format
Writing better specs for 03-03-01-Migrations
Ignoring Gemfile.lock and news.sqlite3 in Git
Redoing 03-04-01-Asociations
Redoing 03-04-02-Seed
Redoing 03-04-03-Validations
Redoing 03-04-04-All-Together-MVC
Merge pull request #28 from lewagon/ar-exos-enhancements

Fixing ActiveRecord exercices
Merge branch 'master' of github.com:lewagon/promo-3-challenges

Conflicts:
	03-AR-Database/03-ActiveRecord-Basics/01-Migrations/lib/interface.rb
find(id) is raising an exception when not found