Entity registry (#11979)

* Entity#unique_id defaults to None

* Initial commit entity registry

* Clean up unique_id property

* Lint

* Add tests to entity component

* Lint

* Restore some unique ids

* Spelling

* Remove use of IP address for unique ID

* Add tests

* Add tests

* Fix tests

* Add some docs

* Add one more test

* Fix new test…

homeassistant/components/binary_sensor/ecobee.py

@@ -50,11 +50,6 @@ class EcobeeBinarySensor(BinarySensorDevice):
         """Return the status of the sensor."""
         return self._state == 'true'
 
-    @property
-    def unique_id(self):
-        """Return the unique ID of this sensor."""
-        return "binary_sensor_ecobee_{}_{}".format(self._name, self.index)
-
     @property
     def device_class(self):
         """Return the class of this sensor, from DEVICE_CLASSES."""