create _tests subdir, py.test based example test module

nsupdate/main/_tests/test_example.py

@@ -0,0 +1,11 @@
+"""
+Tests for xxx module.
+"""
+
+
+class Tests(object):
+    def test_basic_addition(self):
+        """
+        Tests that 1 + 1 always equals 2.
+        """
+        assert 1 + 1 == 2

nsupdate/main/tests.py

@@ -1,16 +0,0 @@
-"""
-This file demonstrates writing tests using the unittest module. These will pass
-when you run "manage.py test".
-
-Replace this with more appropriate tests for your application.
-"""
-
-from django.test import TestCase
-
-
-class SimpleTest(TestCase):
-    def test_basic_addition(self):
-        """
-        Tests that 1 + 1 always equals 2.
-        """
-        self.assertEqual(1 + 1, 2)