Test fixes for Python 2

Author: oschwald

tests/models_test.py

@@ -7,7 +7,14 @@
 sys.path.append('..')
 
 import geoip2.models
-import unittest
+
+if sys.version_info[:2] == (2, 6):
+    import unittest2 as unittest
+else:
+    import unittest
+
+if sys.version_info[0] == 2:
+    unittest.TestCase.assertRaisesRegex = unittest.TestCase.assertRaisesRegexp
 
 
 class TestModels(unittest.TestCase):