Easy Digital Downloads - MailChimp 3.0.16

-Fix: Refund and Cancel methods were not correctly sending information to MailChimp
-Fix: Looking up or Creating a store in MailChimp could throw an exception.
-Fix: MailChimp was inconsistently adding users as transactional when they should be subscribed.

Fix: Fatal PHP error during purchase for some configurations.

• Fix: Fatal error when syncing list and updating products for some sites.