user routes changed. omniauth-kakao added.
added user_activation, structured users_controller simply.
added activation_ticket
email verify added
Complete kakao login cycle.
Need to rescue exceptions, to create views.
Merge with #153 (issue #147)
refactored with user_activator
send activation mail.
removed spec files not used
removed .DS_Store
added user show page, redirect bug fixed.
Merge branch 'feat/can-see-unstructed-comments' of https://github.com/DonutWorks/Ari into feat/can-see-unstructed-comments
#136 url strip & modify error message
피드백 반영
Complete user sign_in/sign_up logic
added model dependency
user_activator test added.
renewal admin/gates/show
fix bug about issue #155
change example format of excel