Update git submodules

* Update docs/submodules/fuel from branch 'master'
  - Merge "Adjust memory allocation size"
  - Adjust memory allocation size

    * [baremetal] add memory to contollers & salt master
    * tune up sysctl vm.dirty* for compute nodes
    * upgrade packages to get the latest versions
      (https://bugs.launchpad.net/cinder/+bug/1641312)

    Change-Id: I9ad22206f2f3f11e1da3f93c7a0931c592adf1cf
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 5c0a09f..4489699 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 5c0a09fbd0f377df56bfcfe94b262225a34f98ff
+Subproject commit 4489699cb63fadb6939d5c70b49e84bb4f1ff17f