[LEARNER-2668]
These changes will support a user intiated Revoke and Refund of
an Entitlement. This includes unenrolling the User from
any related Course Runs they are currently enrolled in.
LEARNER-3438
The user can now enroll in a session, unenroll from a session or change session
from a new course enrollment card on the programs dashboard.
The Entitlement API will allow for GET, POST, DELETE(Revoke), and
variations of these methods of managing and retrieving data about
Learner Entitlements.
[LEARNER-2661]