More pylint 2 fixes (#15565)

## Description:

More fixes flagged by pylint 2 that don't hurt to have before the actual pylint 2 upgrade (which I'll submit soon).

## Checklist:
  - [ ] The code change is tested and works locally.
  - [x] Local tests pass with `tox`. **Your PR cannot be merged unless tests pass**

homeassistant/components/binary_sensor/arest.py

@@ -89,7 +89,7 @@ class ArestBinarySensor(BinarySensorDevice):
         self.arest.update()
 
 
-class ArestData(object):
+class ArestData:
     """Class for handling the data retrieval for pins."""
 
     def __init__(self, resource, pin):