Lesson 5: Modify card_spec
Lesson 5. Add some tests
Lesson 5: Fix errors in card_spec.rb
Lesson 5: Fix some errors in card model
Lesson 5: Fix error when where is no any unreviewed cards
Lesson 5: Fix some git conflicts
Lesson 5: Delete 'any letter' validation
Merge pull request #9 from mfoxtrot/Lesson_5

Lesson 5