"python setup.py test" works

runtests.py

+#!/usr/bin/env python
+
+from os.path import dirname, abspath
+import sys
+
+from django.conf import settings as django_settings
+
+if not django_settings.configured:
+    django_settings.configure(
+        DATABASE_ENGINE='sqlite3',
+        INSTALLED_APPS=(
+            'django.contrib.contenttypes',
+            'taggit',
+            'taggit.tests',
+        )
+    )
+
+def runtests(*test_args):
+    if not test_args:
+        test_args = ['tests']
+    parent = dirname(abspath(__file__))
+    sys.path.insert(0, parent)
+    from django.test.simple import run_tests
+    failures = run_tests(test_args, verbosity=1, interactive=True)
+    sys.exit(failures)
+
+
+if __name__ == '__main__':
+    runtests(*sys.argv[1:])

setup.py

@@ -26,5 +26,6 @@ setup(
         'Programming Language :: Python',
         'Framework :: Django',
     ],
+    test_suite='runtests.runtests'
 )
 

taggit/tests/settings.py

-DATABASE_ENGINE = 'sqlite3'
-
-
-INSTALLED_APPS = [
-    'django.contrib.contenttypes',
-    'taggit',
-    'taggit.tests',
-]