fixed out of stock

db/migrate/20200319113930_drop_out_of_stock_table.rb

@@ -0,0 +1,9 @@
+class DropOutOfStockTable < ActiveRecord::Migration[5.1]
+  def up
+    drop_table :out_of_stocks
+  end
+
+  def down
+    raise ActiveRecord::IrreversibleMigration
+  end
+end