PTKCardExpiry.m Deprecations

[jhergott]

NSGregorianCalendar, NSYearCalendarUnit and NSMonthCalendarUnit were all deprecated in iOS 8.0. They're now NSCalendarIdentifierGregorian, NSCalendarUnitYear and NSCalendarUnitMonth.

[jflinter]

Hey @jhergott,
As part of a large refactor, this code has moved to https://github.com/stripe/stripe-ios, which now has a class called STPPaymentCardTextField that has similar behavior to PTKView. That class doesn't use any deprecated NSCalendar constants, so I'd encourage you to migrate (it should take just a few minutes, and we've written a brief guide at https://github.com/stripe/paymentkit#migration). Of course, if that doesn't work for you, or you have any trouble migrating, reply here and I'll be happy to help.
Cheers!