Moved withdrawn_event check to helper

Signed-off-by: Carlos Coelho <carlos@pencillabs.com>

app/helpers/admin/conference_helper.rb

@@ -0,0 +1,11 @@
+module Admin
+  module ConferenceHelper
+    def withdrawn_events?(conference)
+      conference.program.events.where(state: :withdrawn).empty?
+    end
+
+    def withdrawn_events_count(conference)
+      conference.program.events.where(state: :withdrawn).count
+    end
+  end
+end