Issue for tracking.

Updating api code using DRF.

1. Added standard authentication_classes
2. Added permission_classes

Steps to verify on local tutor instance:

1. Open this page and few data-research roles.
2. Go to this page and go to the bottom of page.
3. From dropdown select the Course Data Researcher.

Expected result:

{
  "course_id": "course-v1:edx+cs222+2311",
  "data_researcher": [
    {
      "username": "admin",
      "email": "[email protected]",
      "first_name": "abc",
      "last_name": "qdd"
    },
    {
      "username": "login_service_user",
      "email": "[email protected]",
      "first_name": "",
      "last_name": ""
    }
  ]
}

• Verified on local via instructor dashboard and also from postman.