Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Pull functest-core when only building childs

    Otherwise it fails if parent and childs containers are not built on
    the same host [1].

    It would have worked if the docker images were correctly cleant. Then
    the last image would have been pulled.

    [1] https://build.opnfv.org/ci/job/functest-apex-baremetal-daily-euphrates/362/console

    Change-Id: I293829c839c1cf68c9f7668aa643e16889359fcc
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 04886b1..e3281b2 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 04886b12a4f5c3f18c71f0ca78fdbcf8a545f5f6
+Subproject commit e3281b2175ca9983d79ce17de7e7497f749e650e