Add @answer to QuestionController#show
User can create answer
User can create answer
Answer erros
User can answers
Add Carrierwave gem and generate file_uploader
add Attachment model
Attachment model
Question accepts nested attributes for attachments
Add files to question
Refactoring
Polymorphic attachments. Answers associated with attachments
User can add files to answers
gitinore update
Refactor question spec and controller
fix spec
refactor with cancan and responders