Do not use relative import

Doesn't work well when running tests.

vpn/apps.py

@@ -1,14 +1,11 @@
 # -*- coding: utf-8 -*-
-from __future__ import unicode_literals
 
+from __future__ import unicode_literals
 from django.apps import AppConfig
 import coin.apps
 
-from . import urls
-
-
 class VPNConfig(AppConfig, coin.apps.AppURLs):
     name = 'vpn'
     verbose_name = "Tunnels VPN"
 
-    exported_urlpatterns = [('vpn', urls.urlpatterns)]
+    exported_urlpatterns = [('vpn', 'vpn.urls')]