remove user promotions report

app/logical/reports/contributors.rb

@@ -1,9 +0,0 @@
-require 'statistics2'
-
-module Reports
-  class Contributors < User
-    def users
-      ::User.where("users.bit_prefs & ? > 0 and users.post_upload_count >= 250", ::User.flag_value_for("can_upload_free")).order("created_at desc").map {|x| Reports::UserPromotions::User.new(x)}
-    end
-  end
-end