实践课程的接口数据调整

app/views/weapps/subjects/index.json.jbuilder

@@ -1,6 +1,7 @@
 json.subjects @subjects do |subject|
   json.(subject, :id, :excellent, :name, :stages_count, :shixuns_count)
   json.myshixuns_count subject.member_count
+  json.challenges_count subject.subject_challenge_count
   json.image_url url_to_avatar(subject)
   json.allow_visit subject.status > 1 || User.current.manager_of_subject?(subject) || User.current.admin?
 end

app/views/weapps/subjects/show.json.jbuilder

@@ -2,6 +2,7 @@ json.subject do
   json.name @subject.name
   json.description @subject.description
   json.shixuns_count @subject.shixuns_count
+  json.challenges_count @subject.subject_challenge_count
   json.member_count @subject.member_count
   json.subject_score @subject.all_score
   json.learning_notes @subject.learning_notes