Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - [salt-formulas] Switch to 'testing' dist

    Nightly repo dist is currently broken.

    Change-Id: I9235c2c95b4edebf56d20e33932237f18a8e63d5
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index e5fba8e..a8f4341 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit e5fba8e323f7886c1e2145903be08ca78ab3c4db
+Subproject commit a8f434118013a69295bdc0f9fc8294c539742c01