asyncio: Fix with github

See https://github.com/python/asyncio/pull/295 for details

Lib/asyncio/test_utils.py

@@ -24,6 +24,7 @@ except ImportError:  # pragma: no cover
     ssl = None
 
 from . import base_events
+from . import compat
 from . import events
 from . import futures
 from . import selectors
@@ -421,6 +422,16 @@ class TestCase(unittest.TestCase):
         # in an except block of a generator
         self.assertEqual(sys.exc_info(), (None, None, None))
 
+    if not compat.PY34:
+        # Python 3.3 compatibility
+        def subTest(self, *args, **kwargs):
+            class EmptyCM:
+                def __enter__(self):
+                    pass
+                def __exit__(self, *exc):
+                    pass
+            return EmptyCM()
+
 
 @contextlib.contextmanager
 def disable_logger():

Lib/test/test_asyncio/test_base_events.py

@@ -782,6 +782,7 @@ class BaseEventLoopTests(test_utils.TestCase):
         self.loop._selector.select.return_value = (event_sentinel,)
 
         for i in range(1, 3):
+            with self.subTest('Loop %d/2' % i):
                 self.loop.call_soon(self.loop.stop)
                 self.loop.run_forever()
                 self.assertEqual(callcount, 1)