Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Refactor resource creation and cleanup in Tempest"
  - Refactor resource creation and cleanup in Tempest

    Use Snaps to create resources before running a testcase and to clean up
    afterwards.
    Use Tempest Cleanup utility to clean other resources.

    Change-Id: Ic0f69d3bafb60dfb283d18ac507e9f5992e9ae38
    Signed-off-by: Martin Kulhavy <martin.kulhavy@nokia.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 172b570..4a228ab 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 172b5709ede1f32b042de621b932f6162f2d89b9
+Subproject commit 4a228ab09e59c5dfa004df0f54df7c20eba2bc0a