[Windows] Security model for files permissions - STEP 2 (#6895)

This PR is the second part of #6497 to ease the integration, following the new plan propose by @bmw here: #6497 (comment)

This PR creates the module certbot.compat.os, that delegates everything to os, and that will be the safeguard against problematic methods of the standard module. On top of that, a quality check wrapper is called in the lint tox environment. This wrapper calls pylint and ensures that standard os module is no used directly in the certbot codebase.

Finally local oldest requirements are updated to ensure that tests will take the new logic when running.

* Add executable permissions

* Add the delegate certbot.compat.os module, add check coding style to enforce usage of certbot.compat.os instead of standard os

* Load certbot.compat.os instead of os

* Move existing compat test

* Update local oldest requirements

* Import sys

* Update account_test.py

* Update os.py

* Update os.py

* Update local oldest requirements

* Implement the new linter_plugin

* Fix local oldest for nginx

* Remove check coding style

* Update linter_plugin.py

* Add several comments

* Update the setup.py

* Add documentation

* Update acme dependencies

* Update certbot/compat/os.py

* Update docs/contributing.rst

* Update linter_plugin.py

* Handle os.path. Simplify checker.

* Add a comment to a reference implementation

* Update changelog

* Fix module registering

* Update docs/contributing.rst

* Update config and changelog

certbot-apache/setup.py

@@ -9,8 +9,8 @@ version = '0.34.0.dev0'
 # Remember to update local-oldest-requirements.txt when changing the minimum
 # acme/certbot version.
 install_requires = [
-    'acme>=0.25.0',
-    'certbot>=0.26.0',
+    'acme>=0.29.0',
+    'certbot>=0.34.0.dev0',
     'mock',
     'python-augeas',
     'setuptools',