Skip test_assertion_in_blocking_func on appveyor.

src/gevent/testing/patched_tests_setup.py

@@ -1291,6 +1291,7 @@ if OSX:
             # These sometime timeout. Cannot reproduce locally.
             'test_ftp.TestTLS_FTPClassMixin.test_mlsd',
             'test_ftp.TestTLS_FTPClassMixin.test_retrlines_too_long',
+            'test_ftp.TestTLS_FTPClassMixin.test_storlines',
         ]
 
     if RESOLVER_ARES and PY38 and not RUNNING_ON_CI:

src/gevent/tests/test__server.py

@@ -469,6 +469,7 @@ class TestNoneSpawn(TestCase):
     def test_invalid_callback(self):
         self._test_invalid_callback()
 
+    @greentest.skipOnAppVeyor("Sometimes doesn't get the error.")
     def test_assertion_in_blocking_func(self):
         def sleep(*_args):
             gevent.sleep(SMALLEST_RELIABLE_DELAY)
@@ -507,7 +508,7 @@ class BadWrapException(BaseException):
 
 class TestSSLGetCertificate(TestCase):
 
-    def _create_server(self):
+    def _create_server(self): # pylint:disable=arguments-differ
         return self.ServerSubClass((greentest.DEFAULT_BIND_ADDR, 0),
                                    keyfile=_file('server.key'),
                                    certfile=_file('server.crt'))