Introduce an Admin::EventScheduleController

- move SchedulesController#update action
- split it into an #create/#update and #destroy action and use these actions in the JS code

spec/factories/event_schedule.rb

@@ -10,13 +10,15 @@ FactoryGirl.define do
       end
       (event_schedule.room = create(:room, venue: venue)) unless event_schedule.room.present?
       (event_schedule.start_time = program.conference.start_date.to_time) unless event_schedule.start_time.present?
-      unless program.selected_schedule.present?
-        schedule = create(:schedule, program: program)
-        program.schedules << schedule
-        program.selected_schedule = schedule
-        program.save!
+      unless event_schedule.schedule.present?
+        unless program.selected_schedule.present?
+          schedule = create(:schedule, program: program)
+          program.schedules << schedule
+          program.selected_schedule = schedule
+          program.save!
+        end
+        event_schedule.schedule = program.selected_schedule
       end
-      event_schedule.schedule = program.selected_schedule
     end
   end
 end