Update git submodules

* Update docs/submodules/fuel from branch 'stable/euphrates'
  - Merge "[MaaS] Override failed testing by default" into stable/euphrates
  - [MaaS] Override failed testing by default

    Some nodes fail automatic testing done by MaaS during commissioning,
    although running the testing suites one more time manually works.
    For now, just override all 'failed testing' nodes unconditionally.

    [stable/euphrates cherry-pick additions]
    Note: Since our salt formulas are pinned to 2017.12 repos, we
    need to backport one salt-formula-maas patch merged upstream, which
    adds support for translating status code '22' to 'Failed testing' [1].

    JIRA: FUEL-333

    [1] https://github.com/salt-formulas/salt-formula-maas/commit/08ffc3ff

    Change-Id: I13d3ee3d82550524480aa53aa8752ab90aa940cd
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit 81561126307f15d4f65a743ed2431ea8c713a921)

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index c5d0050..fe9be64 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit c5d0050fd09db559d9c8f89e8c148ecd7ccedc4f
+Subproject commit fe9be64738ff1a1091e7df5b04b391fb15d6abc0