add bootstrap-switch for is_highlight

app/views/admin/events/_proposal.html.haml

@@ -32,15 +32,9 @@
         %td
           %b Highlight
         %td
-          = link_to "#{@event.is_highlight}".capitalize,
-          admin_conference_event_path(@conference.short_title,
-                                      @event,
-                                      event: { is_highlight: !@event.is_highlight }),
-          method: :patch
-          - if @event.is_highlight
-            (the event is as a highlight and will appear in the splashpage)
-          - else
-            (mark as true to make the event a highlight that appears in the splashpage)
+          = check_box_tag @conference.short_title, @event.id, @event.is_highlight, class: 'switch-checkbox',
+            data: { size: "small" }
+
       %tr
         %td
           %b State