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/sensor/qnap.py

@@ -164,7 +164,7 @@ def round_nicely(number):
     return round(number)
 
 
-class QNAPStatsAPI(object):
+class QNAPStatsAPI:
     """Class to interface with the API."""
 
     def __init__(self, config):