WIP Awais786/course info api

@stephensanchez    We have implemented initial api workflow.  Can you please take a look ?

following is api url.
/api/courseabout/v1/course/about/[course-id]
Nitpick, but if you could move the course about serialization into a function, called by _serialize_content(), that would better reflect the way this module will look once we use Django REST serializers