Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "[virtual] Apply ceilometer/aodh services"
  - [virtual] Apply ceilometer/aodh services

    * run ceilometer/aodh states
    * wrap common virtual cluster options
    * get the source image based on timestamps

    Change-Id: I88f1d63ed4a94eba4ec0a9cf33d36d51c75ae355
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 5f4ea4e..db6e94b 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 5f4ea4eae484a37d1a41e1f5e235285fafccbbe7
+Subproject commit db6e94bc05ad30de2151c2e1ee1dc4fc164f012e