Async syntax 8/8 (#17022)

* Async syntax 8

* Pylint fixes

homeassistant/components/lutron.py

@@ -4,7 +4,6 @@ Component for interacting with a Lutron RadioRA 2 system.
 For more details about this component, please refer to the documentation at
 https://home-assistant.io/components/lutron/
 """
-import asyncio
 import logging
 
 import voluptuous as vol
@@ -69,8 +68,7 @@ class LutronDevice(Entity):
         self._controller = controller
         self._area_name = area_name
 
-    @asyncio.coroutine
-    def async_added_to_hass(self):
+    async def async_added_to_hass(self):
         """Register callbacks."""
         self.hass.async_add_job(
             self._controller.subscribe, self._lutron_device,