Revert to correct the Learners getting errors on SingleBasketItemView…

… ECOM-7349

Release for February 28, 2017

Updated to Django Oscar 1.4

ECOM-7095

Coupon model cleanup

- The URL for the model will always end with a trailing slash
- Minor formatting fixes

ECOM-7096

Update ecommerce enterprise entitlements to account for learner consent

ENT-178: Fix validation of seat types, catalog_query and course_catalog

Preventing Travis from installing requirements.txt

ECOM-3054

Release for February 08, 2017

Updated refund processing methods

- Attempts to approve/deny previously-approved/denied refunds return True
- Attempts to approve/deny refunds in an incorrect state are logged as warnings instead of debug
- Removed unnecessary mocking in test_success_approve_payment_only

ECOM-6975

Disabled refund notifications for free orders

ECOM-6975