Fix #277 -- Embeddable shop (#622)

* Vendor vue.js

* Refactor item_group_by_category to support vouchers

* Widget: Show product list

* Widget: free prices

* Widget: pictures and loading indicator

* Widget: First iframe steps

* Widget: Do not rerender iframe

* Widget: Error handling

* Improve widget

* Widget: localization tech

* Fix invoice style

* Voucher attribute and waiting list

* Add some iframe chrome

* First step to namespaced carts

* More isolation steps

* More cart isolation things

* More cart isolation things

* Mobile stuff

* Show cart on checkout pages

* PayPal and Stripe support

* Enable downloads

* Locale handling

* change text "save URL to this exact page"

* Widget: voucher redemption

* Widget: CSS

* CSS: Responsive

* Widget: CSS improvements

* Widget: Add embedding code generator

* Widget: Error messages and SSL check

* First tests

* Widget: tests

* Don't use IDs in widgets

* Widget: static files caching

src/tests/presale/test_cart.py

@@ -26,9 +26,10 @@ class CartTestMixin:
         self.event = Event.objects.create(
             organizer=self.orga, name='30C3', slug='30c3',
             date_from=datetime.datetime(2013, 12, 26, tzinfo=datetime.timezone.utc),
-            live=True
+            live=True,
+            plugins="pretix.plugins.banktransfer"
         )
-        self.tr19 = self.event.tax_rules.create(rate=19)
+        self.tr19 = self.event.tax_rules.create(rate=Decimal('19.00'))
         self.category = ItemCategory.objects.create(event=self.event, name="Everything", position=0)
         self.quota_shirts = Quota.objects.create(event=self.event, name='Shirts', size=2)
         self.shirt = Item.objects.create(event=self.event, name='T-Shirt', category=self.category, default_price=12,