anchor.diff:  ### List All Courses [GET /courses{?quarter_id,professor_id}]
   
   + Parameters
  -    + quarter_id (optional, number) - Limit the list to courses that were taught during the specified quarter
  -    + professor_id (optional, number) - Limit the list to courses that were taught by the specified professor
  +    + quarter_id (number, optional) - Limit the list to courses that were taught during the specified quarter
  +    + professor_id (number, optional) - Limit the list to courses that were taught by the specified professor
   
   + Response 200 (application/json)
       + Attributes (array[Course], fixed-type)
  +
  +
  +### List Top Courses [GET /courses/top{?count,department_id}]
  +
  ++ Parameters
  +    + count (number, optional)
  +        + Default: 5
  +    + department_id (array[number], optional)
  +
  ++ Response 200 (application/json)
  +    + Attributes (array, required, fixed-type)
  +        + (object, required)
  +            + course (Course, required)
  +            + avg_score: 3.0 (number, required)
  +            
  ++ Response 404 (application/json)
  +    + Attributes
  +        + message: `department with id <id> not found` (string, required)
  +
   
   ### Post Courses [POST]
   
  
positive.code:     + course_id: 1 (number, optional)
      + quarter_id: 1 (number, optional)
      + embed (array, optional)
          + (enum)
              + professor
              + course
  
  
negative.code:     + professor_id: 1 (number, optional)
      + course_id: 1 (number, optional)
      + quarter_id: 1 (number, optional)
      + embed (array[string], optional) - Specify one or more of the following: professor, course.
  
  + Response 200 (application/json)
      + Attributes (array, required, fixed-type)
  