add carrierwave and generate model Attachment
Attachment model and association
add accept nested attributes
add file to question (save)
add delete answer spec
add destroy spec to answer controller
add ajax
add carrierwave and generate model Attachment
Attachment model and association
add accept nested attributes
add file to question (save)
before rebase
before rebase master
fix test fail
add file to question end
Merge branch 'add_file_to_question', remote-tracking branch 'remotes/origin/add_file_to_question'

Conflicts:
	app/uploaders/file_uploader.rb
	app/views/questions/_answers.html.slim
	app/views/questions/_question.html.slim
	spec/acceptance/question/add_file_to_question_spec.rb
add spec file
add polimorphic assotiations (model test)
add attachment to answer end