anchor.diff:  
   CaμsAPI is an API to promote utility learning assistant on wechat end.
   
  -## Student Register [/students/register]
  +## Student Register [/users/register]
   
   ### A Student Register [POST]
   
  
positive.code:             "username": "Request username"
          }
  
  ## Student Course Assignments List [/learnhelper/{username}/{semester}/courses/{courseid}/assignments]
  
  ### Get All Assignments Of A Course [POST]
  
  
negative.code:             "username": "Request username"
          }
  
  ## Student Courses List [/learnhelper/{username}/courses]
  
  ### A Student Get His Courses List [POST]
  
  