Rename module async to tasks (#994)

Fixes #993

src/pretix/control/views/orders.py

@@ -50,8 +50,8 @@ from pretix.base.services.orders import (
 from pretix.base.services.stats import order_overview
 from pretix.base.signals import register_data_exporters
 from pretix.base.templatetags.money import money_filter
-from pretix.base.views.async import AsyncAction
 from pretix.base.views.mixins import OrderQuestionsViewMixin
+from pretix.base.views.tasks import AsyncAction
 from pretix.control.forms.filter import EventOrderFilterForm, RefundFilterForm
 from pretix.control.forms.orders import (
     CommentForm, ExporterForm, ExtendForm, MarkPaidForm, OrderContactForm,

src/pretix/control/views/shredder.py

@@ -11,7 +11,7 @@ from django.views.generic import TemplateView
 from pretix.base.models import CachedFile
 from pretix.base.services.shredder import export, shred
 from pretix.base.shredder import ShredError, shred_constraints
-from pretix.base.views.async import AsyncAction
+from pretix.base.views.tasks import AsyncAction
 from pretix.control.permissions import EventPermissionRequiredMixin
 
 logger = logging.getLogger(__name__)

src/pretix/control/views/waitinglist.py

@@ -18,7 +18,7 @@ from django.views.generic.edit import DeleteView
 from pretix.base.models import Item, WaitingListEntry
 from pretix.base.models.waitinglist import WaitingListException
 from pretix.base.services.waitinglist import assign_automatically
-from pretix.base.views.async import AsyncAction
+from pretix.base.views.tasks import AsyncAction
 from pretix.control.permissions import EventPermissionRequiredMixin
 from pretix.control.views import PaginationMixin