Django 1.8 alpha 1 support

* Test on Python 2.7, 3.4, pypy.
* Call super.setUpClass in DjrillAdminTests.
  https://docs.djangoproject.com/en/dev/releases/1.8/#overriding-setupclass-teardownclass-in-test-cases

Also clear up some new PendingDeprecationWarnings, where
the changes can easily remain compatible back to Django 1.3:

* Remove deprecated django.conf.urls.patterns.
  (And match Django recommendations in our docs.)
  https://docs.djangoproject.com/en/dev/releases/1.8/#django-conf-urls-patterns
* Remove deprecated SimpleTestCase.urls.
  (We've already back-ported @override_settings
  for testing older Django versions.)
  https://docs.djangoproject.com/en/dev/releases/1.8/#django-test-simpletestcase-urls

djrill/urls.py

@@ -1,13 +1,11 @@
 try:
-    from django.conf.urls import patterns, url
+    from django.conf.urls import url
 except ImportError:
-    from django.conf.urls.defaults import patterns, url
+    from django.conf.urls.defaults import url
 
 from .views import DjrillWebhookView
 
 
-urlpatterns = patterns(
-    '',
-
+urlpatterns = [
     url(r'^webhook/$', DjrillWebhookView.as_view(), name='djrill_webhook'),
-)
+]