Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "Double allocated memory of fuel master node"
  - Double allocated memory of fuel master node

    Rise up allocated memory of fuel master node for virtual envs in order
    to avoid swapping and improve performance of overall deployment process.

    Change-Id: I04b020b628a9c84f934a9d17e8be98d34fe2a085
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 86eaf30..2e6b10e 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 86eaf30b6b76d6ca1acbea243d2fdf100df43388
+Subproject commit 2e6b10e3767fd476b288415949b9d049174e00cc