fix bug about issue #155
renewal admin/gate new, edit view
Merge branch 'develop' of https://github.com/DonutWorks/Ari into develop
#163 modify header, table design
#157 add slack noti for donutworks operation'
#163 create admin/user/show & move buttons in view
#165 modifying routes.rb
help-block added.
bootstrap-scss gem added instead of raw bootstrap.
renewal admin/gate new, edit view
help-block added.
using gem to export excel
Moved methods of Admin::Users::RegistrationsController to Admin::UsersController
renewal users/new, edit
apply rails-i18n
bug fixed about submitting without file
bug fixed about column name is blank
erase unused file
Merge branch 'develop' of https://github.com/DonutWorks/Ari into fix-bug-about-issue-#155

Conflicts:
	app/controllers/admin/import_controller.rb
Merge pull request #170 from DonutWorks/fix-bug-about-issue-#155

Fix bug about issue #155