Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "prototypes: xci: Add ability to use local repositories for testing"
  - prototypes: xci: Add ability to use local repositories for testing

    When developing XCI features it's useful to be able to use the local
    repositories rather than cloning them from git since that makes
    it harder to test local modifications against XCI. As such, we add
    three new variables which can be used to hold local paths to the
    bifrost, releng and openstack-ansible repositories. We are still
    cloning the repositories but we then use the 'synchronize' Ansible
    module to copy modified files from the local repositories.

    Change-Id: I6d593ea48d8b9c51415d9d0848f77a498ef2f486
    Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 679c6f7..331b167 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 679c6f76d09a386ce4d9d08ad85e59490b829d50
+Subproject commit 331b1671696fdc7823332add1f48b6ce90b99c75