Enable PEP8 checks for F401, E202, E271, E272, E711, E712

* F401 module imported but unused
* E271 multiple spaces after keyword
* E272 multiple spaces before keyword
* E202 remove extraneous whitespace
* E711 comparison to None should be 'if cond is None:'
* E712 comparison to True/False should be 'if cond is True/False:' or 'if cond:'

Change-Id: I56a1dbee2ae17b8315a55215e2c676e0de8311f7

packstack/installer/validators.py

@@ -8,13 +8,9 @@ import os
 import re
 import socket
 import logging
-import tempfile
-import traceback
 
-import basedefs
 from . import utils
 
-from .setup_controller import Controller
 from .exceptions import ParamValidationError