Fix missing import.

biscuit/apps/alsijil/views.py

@@ -5,6 +5,7 @@ from django.contrib.auth.decorators import login_required
 from django.db.models import Count, Exists, OuterRef, Q, Sum
 from django.http import Http404, HttpRequest, HttpResponse
 from django.shortcuts import render
+from django.urls import reverse
 from django.utils.translation import ugettext as _
 from django.views.decorators.cache import cache_page