Update git submodules

* Update docs/submodules/functest from branch 'stable/euphrates'
  - Disable Promise testsuite on Fuel installer

    When promise reads API v3.0 from the creds file it automatically
    uses v2.0. which is deprecated and not used by fuel. Therefore
    promise is removed from the functest suite

    JIRA: ARMBAND-314

    Change-Id: I22b875c198c1922fd4ddb06c81c05884b5248eb4
    Signed-off-by: Charalampos Kominos <Charalampos.Kominos@enea.com>
    (cherry picked from commit 8c3791f730effbf09fc95ef2bc66ff0d0a37e87b)

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 6034156..0b15334 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 6034156f81644bf02b93985acd732afd34c770e1
+Subproject commit 0b15334d7f241d4da822d7c843fd2dfc5d1fdbac