mv lib to app/lib use :zeitwerk

db/migrate/021_remove_table_article_prices.rb

@@ -16,7 +16,7 @@ class RemoveTableArticlePrices < ActiveRecord::Migration[4.2]
     puts "now copy values of article_prices into new articles-columns..."
     Article.find(:all).each do |article|
       price = article.current_price
-      article.update_attributes!(:clear_price => price.clear_price,
+      article.update!(:clear_price => price.clear_price,
                                  :gross_price => price.gross_price,
                                  :tax => price.tax,
                                  :refund => price.refund,

db/migrate/20090120184410_road_to_version_three.rb

@@ -47,7 +47,7 @@ class RoadToVersionThree < ActiveRecord::Migration[4.2]
     Ordergroup.all.each do |ordergroup|
       contact = ordergroup.users.first
       if contact
-        ordergroup.update_attributes :contact_person => contact.name,
+        ordergroup.update :contact_person => contact.name,
                                      :contact_phone => contact.phone, :contact_address => contact.address
       end
     end

db/migrate/20130622095040_move_weekly_tasks.rb

@@ -27,7 +27,7 @@ class MoveWeeklyTasks < ActiveRecord::Migration[4.2]
           task_required_users: task.required_users,
           task_duration: task.duration
         }
-        workgroup.update_attributes workgroup_attributes
+        workgroup.update workgroup_attributes
         task_group.tasks.update_all weekly: true
       end
     end