Support per-user limits on coupons.  This restricts users from placing multiple
orders with the same discount.  This is a commonly used feature in magento for sites
that have a max $ limit on their coupons.  Users bypass this by placing multiple orders.
Magento however doesn't force you to be logged in during the time of ordering, so it's easly bypassed
that system.
Include PHPUnit since it's not required by behat to run, but we're using it in WebBundle/Behat/WebUser.php
Merge branch 'master' of github.com:mykehsd/Sylius