Add setUpClass and tearDownClass to unittest.TestCase in Python 2 stub (#1760)

stdlib/2/unittest.pyi

@@ -55,6 +55,10 @@ class TestCase(Testable):
     def __init__(self, methodName: str = ...) -> None: ...
     def setUp(self) -> None: ...
     def tearDown(self) -> None: ...
+    @classmethod
+    def setUpClass(cls) -> None: ...
+    @classmethod
+    def tearDownClass(cls) -> None: ...
     def run(self, result: TestResult = ...) -> None: ...
     def debug(self) -> None: ...
     def assert_(self, expr: Any, msg: object = ...) -> None: ...