Update the redeem code schema

Updating the redeem code schema.

Adding migration file.

Adding course mode support when redeeming a code.

Conflicts:
	lms/djangoapps/shoppingcart/views.py

Add sales admin privileges for redeem code generation.

Making sure redeem code URLs work for verified courses.

pep8 violations

Code Review and Test Cleanup changes

Added tests, fixed tests.

Updating the boolean checks in ecommerce template