Created discount models
Implement basic discounts controller and spec
Add ability to select events for each discount
Added delete tests for discounts controller
Prevent user from applying discount to events they do not own
Add discount support at checkout
Add live update for discounts at checkout
Add client-side validation to discount code
Add control group to non-user form as well
Add ability to disable discounts
Fix discount edit form on error
Add discount limiting and limit errors
Merge pull request #5 from lanceulmer/discounts

Implemented Discounts
add global payment env variable to spec
show the right total price, formatted, on the receipt
fixed coffee script not updating total cost of a grand total discount was being used
make sure total cost does not go below 0 with discounts