Update git submodules

* Update docs/submodules/fuel from branch 'stable/euphrates'
  - [virtual] Switch compute nodes to uca repo

    Test of snaps_health_check gets console output of instance, which is
    empty (https://bugs.launchpad.net/ubuntu/+source/libvirt/+bug/1667033),
    therefore take affected packages of computes from UCA repo.

    Change-Id: I4e13a40dd47caf305efd9f393b3c3cf5a17ef312
    Signed-off-by: Michael Polenchuk <mpolenchuk@mirantis.com>
    (cherry picked from commit c76d5e92d9e6cdfc614be4a1ed7b9e630c711008)

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 533b81d..a27ad89 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 533b81df35acd7c2f16cd347cf3167583e870d38
+Subproject commit a27ad89c0d97ff1be7f40af51b59df8d26dc7fe4