Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Revert "patches: Drop salt ver sync patch, now upstream"

    Unlike nightly dist, stable/2017.12 distributions of salt formulas
    repo do not yet include this change, so bring it back.

    This reverts commit 8fbafdf8a665fb8fff4d6f9f14c343e109c122ec.

    Change-Id: I7f7011750d385a28f4653faeeb74edb1cac1bcf2
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 6e0e518..c3120b5 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 6e0e518d43cecfb8f981dbd51326d8eae103720c
+Subproject commit c3120b572e9a76018128512a809ddbb00098f551