课程所包含的子功能模块(enabled_modules)相关逻辑修改

app/models/member.rb

@@ -22,8 +22,9 @@ class Member < ActiveRecord::Base
   has_many :roles, :through => :member_roles
   
   belongs_to :project
+  belongs_to :course
 
-  validates_presence_of :principal, :project
+  validates_presence_of :principal
   validates_uniqueness_of :user_id, :scope => :project_id
   validate :validate_role