Version 2.7.2

• Require export files #296
• Writeable and updatable coupon description #297
• Adds a getType method to all Resources #299
• The Pager should implement the Countable interface (thanks to naderman) #282
• Parse incorrectly shaped validation errors #298
• Adds external payments to invoices #309
• GiftCard: deliver_at goes on the Delivery object #307
• Changes for API v2.5 #310