* Correct docblock
* Implement coupons endpoint with add/delete/get functionality
* Add totals
* Use money formatting
* Added tests for new endpoints
* Add coupons to main cart endpoint and update docs to match
* Fix indenting in readme
* is_a to instanceof
* Update coupon_exists logic
* Documentation/tidy class
* Update currency responses for coupon totals w/ tests
Mike Jolley