Add contestant export feature

app/controllers/contestants_controller.rb

@@ -111,6 +111,19 @@ class ContestantsController < ApplicationController
     end
   end
 
+  def export
+    authorize @contest
+
+    @contestants = @contest.contestants.sort_by { |contestant| [ -contestant.completions.size, contestant.time_seconds ] }
+
+    respond_to do |format|
+      format.csv do
+        response.headers["Content-Type"] = "text/csv"
+        response.headers["Content-Disposition"] = "attachment; filename=export.csv"
+      end
+    end
+  end
+
   private
 
   def set_contest