Allow duping promo

Author: ericholscher

readthedocs/donate/admin.py

@@ -49,6 +49,7 @@ def click_ratio(self, instance):
 
 class SupporterPromoAdmin(admin.ModelAdmin):
     model = SupporterPromo
+    save_as = True
     list_display = ('name', 'live', 'click_ratio', 'sold_impressions',
                     'total_views', 'total_clicks')
     list_filter = ('live', 'display_type')