Skip failing openssl 1.1.1 tests (for now)

One tests fails when using openssl 1.1.1 with TLS 1.3 support. Disable
this test for now. Please fix the bug in tornado and re-enable it again.

Bug: tornadoweb/tornado#2536

tests/unit/utils/test_event.py

@@ -360,6 +360,8 @@ def _handle_publish(self, raw):
         self.tag, self.data = salt.utils.event.SaltEvent.unpack(raw)
         self.stop()
 
+    @skipIf(True, "Failing when using openssl 1.1.1 with TLS 1.3 support. "
+                  "See https://github.com/tornadoweb/tornado/issues/2536")
     def test_event_subscription(self):
         '''Test a single event is received'''
         me = salt.utils.event.MinionEvent(self.opts, listen=True)