* Feature - Add bulk PDF generation to vouchers list
* Tweak - Add the ability to filter the voucher list by voucher template
* Fix - Add compatibility for using some offloaded media as voucher images
* Misc - Require WooCommerce 3.0+
* Fix - Improve barcode scanning browser support and give more helpful error messages when it fails
* Fix - Fix a bug preventing barcode scanning from working at all in Microsoft Edge
