adds task for updating the hot_score in debates

lib/tasks/debates.rake

@@ -0,0 +1,9 @@
+namespace :debates do
+  desc "Updates all debates by recalculating their hot_score"
+  task hot_score: :environment do
+    Debate.find_in_batches do |debates|
+      debates.each(&:save)
+    end
+  end
+
+end