WordPress Coding Standards no camel case.
Don't schedule all events directly, instead we schedule events after each other it the status is still open.
Always use the payment id as invoice number, this way we can always use this value from Buckaroo push requests.
Show the Buckaroo push URI to users.
Also added support for $_GET push requests.
Removed Buckaroo class, now part of the WordPress Pay Buckaroo library, installed with Composer.
Enabled Buckaroo listener.
Getting ready for version 2.8.4.
Merge branch 'release/2.8.4'