Address asyncio comments (#3663)

* Template platforms: create_task instead of yield from

* Automation: less yielding, more create_tasking

* Helpers.script: less yielding, more create_tasking

* Deflake logbook test

* Deflake automation reload config test

* MQTT: Use async_add_job and threaded_listener_factory

* Deflake other logbook test

* lint

* Add test for automation trigger service

* MQTT client can be called from within async

tests/components/test_logbook.py

@@ -50,6 +50,11 @@ class TestComponentLogbook(unittest.TestCase):
             logbook.ATTR_ENTITY_ID: 'switch.test_switch'
         }, True)
 
+        # Logbook entry service call results in firing an event.
+        # Our service call will unblock when the event listeners have been
+        # scheduled. This means that they may not have been processed yet.
+        self.hass.block_till_done()
+
         self.assertEqual(1, len(calls))
         last_call = calls[-1]
 
@@ -70,6 +75,11 @@ class TestComponentLogbook(unittest.TestCase):
         self.hass.bus.listen(logbook.EVENT_LOGBOOK_ENTRY, event_listener)
         self.hass.services.call(logbook.DOMAIN, 'log', {}, True)
 
+        # Logbook entry service call results in firing an event.
+        # Our service call will unblock when the event listeners have been
+        # scheduled. This means that they may not have been processed yet.
+        self.hass.block_till_done()
+
         self.assertEqual(0, len(calls))
 
     def test_humanify_filter_sensor(self):