Test tweaks (#11560)

* Fix is_allowed_path on OS X

* Move APNS2 inside func in test

tests/test_core.py

@@ -797,8 +797,10 @@ class TestConfig(unittest.TestCase):
     def test_is_allowed_path(self):
         """Test is_allowed_path method."""
         with TemporaryDirectory() as tmp_dir:
+            # The created dir is in /tmp. This is a symlink on OS X
+            # causing this test to fail unless we resolve path first.
             self.config.whitelist_external_dirs = set((
-                tmp_dir,
+                os.path.realpath(tmp_dir),
             ))
 
             test_file = os.path.join(tmp_dir, "test.jpg")