实训关卡得分默认值设置为100分，并迁移以往分数为空的数据

Gemfile

@@ -15,7 +15,7 @@ unless RUBY_PLATFORM =~ /w32/
   gem 'nokogiri'
 end
 
-gem 'simple_xlsx_reader'
+#gem 'simple_xlsx_reader'
 gem 'wechat',path: 'lib/wechat'
 gem 'grack', path:'lib/grack'
 gem 'gitlab', path: 'lib/gitlab-cli'

db/migrate/20170922114504_add_score_default_value_for_challenge.rb

@@ -0,0 +1,10 @@
+class AddScoreDefaultValueForChallenge < ActiveRecord::Migration
+  def up
+    challenges = Challenge.where(:score => nil)
+    challenges.update_all(:score => 100)
+    change_column :challenges, :score, :integer, :default => 100
+  end
+
+  def down
+  end
+end