Update git submodules

* Update docs/submodules/functest from branch 'stable/fraser'
  - Temporarily switch to collivier/abot_charm

    It hosts a key fix which should be merged in the right repo.
    This patch can be safely reverted as soon as [1] is merged.

    [1] https://github.com/RebacaInc/abot_charm/pull/3

    Change-Id: If98d163ecd2ce6b50c08d8dad886c0d4b2c39a34
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
    (cherry picked from commit d2c129f8319503a8fabe5b87c71737845f06ab36)

diff --git a/docs/submodules/functest b/docs/submodules/functest
index 5400c81..f837ff6 160000 (submodule)
--- a/docs/submodules/functest
+++ b/docs/submodules/functest
@@ -1 +1 @@
-Subproject commit 5400c8133810b7538f26b83b30e9ab5be29f79c6
+Subproject commit f837ff665a563430c693e47125dcc14fec2aec91