Cookbook refactored
Merge pull request #25 from lewagon/cookbook-refactored

Cookbook refactored
Commit before teacher
after teacher
Rakefile to check file exists
Count lines to validate exercise
Rakefile testing CSS file size
All CSS exercises tested
Invert arity
Test bootstrap grid exercise
Need 3 html files
Empty 0/0 tests for JS exercises
Merge branch 'master' of github.com:lewagon/promo-3-challenges
in course