迁移文件调整

db/migrate/20190426010412_add_is_invalid_to_student_works_scores.rb

@@ -1,6 +1,6 @@
 class AddIsInvalidToStudentWorksScores < ActiveRecord::Migration[5.2]
   def change
-    # add_column :student_works_scores, :is_invalid, :boolean, default: false
+    add_column :student_works_scores, :is_invalid, :boolean, default: false
 
     StudentWorksScore.where("score is not null").order("id desc").find_each do |score|
       unless score.is_invalid