v2.0.0

This release is bringing you a multitude of changes - Thank you everyone who contributed!

First and foremost: The version was bumped to 2.0.0. All future developments on in the 2.0.0 line will only be maintaining compatibility with pretix 2.x. If you are still running an older version of pretix 1.x, please only use a plugin with a 1.x-version.

In other news, the displaying of the QR-code has now completely been removed, as it relied on pretix-cashpoint being installed - as this plugin has been deprecated and its functionality can be achieved using the official API, there is no need to keep this legacy stuff around.

Furthermore, a translation for pt_BR has been contributed by @samifor - thanks!

A big "Thank you!" also goes to pretix' maintainer @raphaelm who did the hard lifting and single-handedly ported the plugin to pretix 2.0 ✨