Add isort and flake8 to CI (#869)

* Run isort.

* Clean up unused assignments.

* Add flake8 linting step.

plugins/module_utils/crypto/_objects.py

@@ -5,11 +5,14 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 from __future__ import absolute_import, division, print_function
+
+
 __metaclass__ = type
 
 
 from ._objects_data import OID_MAP
 
+
 OID_LOOKUP = dict()
 NORMALIZE_NAMES = dict()
 NORMALIZE_NAMES_SHORT = dict()