spec: compact and dry question model and add check answers
challenge: minor ui change and route change
challenge: helper+spec update
rspec: more on challenges_helper and cleanup some code
challenge: move question_types from helper to class method types
challenge: fixed from change to Question.types
remove choice and answer from the app
spec: remove unneccessary spec files
Merge branch 'master' of github.com:kick-start/ror-course
Merge branch 'master' of github.com:kick-start/ror-course