Add unit test for quiz false positivies
Split section classification to separate files

Maybe have a sections folder in the future and one per type
(quiz/exercise/normal) ?
Rewrite quiz logic to be more robust

Fixes #470
Allow quiz titles in validation
Merge pull request #472 from GitbookIO/fix/quizzes

Fix/quizzes
Bump version to 1.1.1
Merge branch 'master' of github.com:GitbookIO/gitbook into ebook_hook