Add module 'write-files-deferred' executed in stage 'final' (#916)

The main idea is to introduce a second module that takes care of
writing files, but in the 'final' stage.

While the introduction of a second module would allow for choosing
the appropriate place withing the order of modules (and stages),
there is no addition top-level directive being added to the cloud
configuration schema. Instead, 'write-files' schema is being extended
to include a 'defer' attribute used only by the 'write-deffered-files'
modules.

The new module 'write-deferred-files' reuses as much as
possible of the 'write-files' functionality.

1 files changed, 1 insertions, 0 deletions

diff --git a/tests/unittests/test_handler/test_schema.py b/tests/unittests/test_handler/test_schema.py
index 6f37ceb7..59f58f7c 100644
--- a/tests/unittests/test_handler/test_schema.py
+++ b/tests/unittests/test_handler/test_schema.py
@@ -34,6 +34,7 @@ class GetSchemaTest(CiTestCase):
                 'cc_ubuntu_advantage',
                 'cc_ubuntu_drivers',
                 'cc_write_files',
+                'cc_write_files_deferred',
                 'cc_zypper_add_repo',
                 'cc_chef'
             ],