Update git submodules

* Update docs/submodules/functest from branch 'stable/fraser'
  - Check app workload in juju_epc

    It avoids interpreting rsync errors in case of deployment failures.
    Mysql is still unchecked.

    Change-Id: I01b4470b86637d0fc322c422f05240a928305158
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 15bed39..78d628c 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 15bed392750c02152ca10fed056a63b1eaee7cf2
+Subproject commit 78d628c929b02112dfb86dc9dfe9830ed1d5f975