update urls.pyes to use path() and add some tests

karma/urls.py

@@ -1,16 +1,16 @@
 """URL patterns for the karma views."""
-
-from django.conf.urls import url, include
+from django.conf.urls import include
+from django.urls import path
 from rest_framework.routers import DefaultRouter
 
-from karma.views import key_detail, index, KarmaKeyViewSet
+from karma.views import KarmaKeyViewSet, index, key_detail
 
 router = DefaultRouter()
 router.register(r'keys', KarmaKeyViewSet)
 
 urlpatterns = [
-    url(r'^$', index, name='karma_index'),
-    url(r'^key/(?P<karma_key>.+)/', key_detail, name='karma_key_detail'),
+    path('', index, name='karma_index'),
+    path('key/<karma_key>/', key_detail, name='karma_key_detail'),
 
-    url(r'^api/', include(router.urls)),
+    path('api/', include(router.urls)),
 ]