tests: Add unittest aliases to Python 2.7

tests/test_module.py

@@ -26,6 +26,15 @@ PYTHON = sys.executable or 'python'
 
 
 class ModuleTestCase(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        super(ModuleTestCase, cls).setUpClass()
+
+        # https://docs.python.org/3/library/unittest.html#deprecated-aliases
+        if sys.version_info < (3, 2):
+            cls.assertRegex = cls.assertRegexpMatches
+            cls.assertRaisesRegex = cls.assertRaisesRegexp
+
     def setUp(self):
         self.wd = tempfile.mkdtemp(prefix='yamllint-tests-')