Update git submodules

* Update docs/submodules/promise from branch 'master'
  - Removed unnecessary logs

    Change-Id: I36e086d442d589535b5b645ef8207a5848c7b654
    Signed-off-by: Bertrand Souville <souville@docomolab-euro.com>

diff --git a/docs/submodules/promise b/docs/submodules/promise
index b121b21..6dc47be 160000 (submodule)
--- a/docs/submodules/promise
+++ b/docs/submodules/promise
@@ -1 +1 @@
-Subproject commit b121b21df581291cd273a9a8acc1d4f266116022
+Subproject commit 6dc47bec9e4e23b744c9d74c4fb4846604e7b808