Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - [baremetal] Setup glusterfs for nova instances

    Live-migration feature requires shared storage on compute nodes,
    so configure glusterfs volume for nova instances.

    Change-Id: Id6b9b5aad89f5b4aefbef71e4ba7247a441873b0
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index b30697a..68209af 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit b30697a84ce41ee20a8b6070acda60f3a5cfac26
+Subproject commit 68209af58a0b1bcd110b2c12fcfc9687ed970da4