Fix Django test app manage.py for Django >= 1.4.

tests/testapp/manage.py

@@ -1,19 +1,13 @@
 #!/usr/bin/env python
-from django.core.management import execute_manager
-import imp
+import os
+
+from django.core.management import execute_from_command_line
 
 #Added for test runner
 import os, sys
 sys.path.insert(0, os.path.abspath('./../../'))
 
-try:
-    imp.find_module('settings') # Assumed to be in the same directory.
-except ImportError:
-    import sys
-    sys.stderr.write("Error: Can't find the file 'settings.py' in the directory containing %r. It appears you've customized things.\nYou'll have to run django-admin.py, passing it your settings module.\n" % __file__)
-    sys.exit(1)
-
-import settings
 
 if __name__ == "__main__":
-    execute_manager(settings)
+    os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'settings')
+    execute_from_command_line()