Create devise for users.
Add user to questions.
Add bootstrap.
Add cancan.
Fix tests.
Translate html.erb to slim.
Add Answer model.
Add creating new answer and showing all answers of question.
Add update and destroy for answer.
Add role to User.
Add rights restriction to Question and Answer.
Add 403 page.
Add tests for access to question controller.
Add acts-as-taggable-on gem.
Create adding tags to question.
Display  question's tags.
Add new already checked tag.
Add tests for tags.
Add tag cloud.
Add questions filtering  by tags.