Python 3.8 collections compatibility fixes.

Includes a new pylint blacklist plugin to prevent regressions.

lib/ansible/plugins/test/core.py

@@ -21,10 +21,10 @@ __metaclass__ = type
 
 import re
 import operator as py_operator
-from collections import MutableMapping, MutableSequence
 from distutils.version import LooseVersion, StrictVersion
 
 from ansible import errors
+from ansible.module_utils.common._collections_compat import MutableMapping, MutableSequence
 
 try:
     from __main__ import display