Rewrote Credit API

- API built atop Django REST Framework
- Added support for OAuth 2.0 and session authentication
- Added permissions around eligibility data

ECOM-2609

lms/envs/common.py

@@ -393,9 +393,6 @@ FEATURES = {
     # Enable OpenBadge support. See the BADGR_* settings later in this file.
     'ENABLE_OPENBADGES': False,
 
-    # Credit course API
-    'ENABLE_CREDIT_API': True,
-
     # The block types to disable need to be specified in "x block disable config" in django admin.
     'ENABLE_DISABLING_XBLOCK_TYPES': True,