Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "Update PTL"
  - Update PTL

    Election process
    https://lists.opnfv.org/pipermail/opnfv-tech-discuss/2018-May/021163.html

    Change-Id: Id12673df1797afe0af16812bdf67b8ca8a931626
    Signed-off-by: Cristina Pauna <cristina.pauna@enea.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 421aa57..111e21e 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 421aa5796c194382bec24737b9b1d60bde544672
+Subproject commit 111e21e54a6b5a29f19e504fddfaf03b7370175e