Update git submodules

* Update docs/submodules/fuel from branch 'stable/euphrates'
  - Merge "Enable options for customizing deploy workflow" into stable/euphrates
  - Enable options for customizing deploy workflow

    Change-Id: I1011734895771fdaf653c59348a9ce0aeeff47a7
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>
    (cherry picked from commit a10b7711ab3d400830406a2c425acb3431b4a5c1)

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index c60e591..3e423ea 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit c60e5913d2c563c77d1e69a87f900e9fbf47eba7
+Subproject commit 3e423ea189bdb00e648a263a6c31a285661e736b