style(rubocop): fix all safe auto correctable offenses

db/migrate/20180216114344_add_host_to_authie_sessions.authie.rb

@@ -1,6 +1,8 @@
 # This migration comes from authie (originally 20180215152200)
 class AddHostToAuthieSessions < ActiveRecord::Migration[4.2]
+
   def change
     add_column :authie_sessions, :host, :string
   end
+
 end