Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Setup mongodb master primarily

    Initiate mongodb master at first to avoid race conditaion with
    unwanted master election which causes cluster setup failure.

    Change-Id: I6d2f75f3f002849cac3a5f52a7dcfb4646b7822a
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 1ea4959..97b36af 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 1ea49591080442d8db86fff60031d3dc41142274
+Subproject commit 97b36af156a059cf2568b046cf5d0871562348ff