Integration Testing: tox env, pyxld 2.2.3, and revamp framework

Massive update to clean up and greatly enhance the integration testing
framework developed by Wesley Wiedenmeier.

 - Updated tox environment to run integration test 'citest' to utilize
   pylxd 2.2.3
 - Add support for distro feature flags
   - add framework for feature flags to release config with feature groups
     and overrides allowed in any release conf override level
   - add support for feature flags in platform and config handling
   - during collect, skip testcases that require features not supported by
     the image with a warning message
 - Enable additional distros (i.e. centos, debian)
 - Add 'bddeb' command to build a deb from the current working tree
   cleanly in a container, so deps do not have to be installed on host
 - Adds a command line option '--preserve-data' that ensures that
   collected data will be left after tests run. This also allows the
   directory to store collected data in during the run command to be
   specified using '--data-dir'.
 - Updated Read the Docs testing page and doc strings for pep 257
   compliance

1 files changed, 2 insertions, 2 deletions

diff --git a/tests/cloud_tests/testcases/examples/__init__.py b/tests/cloud_tests/testcases/examples/__init__.py
index b3af7f8a..39af88c2 100644
--- a/tests/cloud_tests/testcases/examples/__init__.py
+++ b/tests/cloud_tests/testcases/examples/__init__.py
@@ -1,7 +1,7 @@
 # This file is part of cloud-init. See LICENSE file for license information.
 
-"""
-Test verifiers for cloud-init examples
+"""Test verifiers for cloud-init examples.
+
 See configs/examples/README.md for more information
 """