Update git submodules

* Update docs/submodules/calipso from branch 'master'
  - Python 3.4 backwards compatibility (for 'verify' job)

    cherry-picked from internal commit by ilia on 07/02/2018 19:49

    Change-Id: I03caf42492785a9af5e8301ca202b00a7b4af787
    Signed-off-by: yayogev <yaronyogev@gmail.com>

diff --git a/docs/submodules/calipso b/docs/submodules/calipso
index 648a394..2e47d87 160000 (submodule)
--- a/docs/submodules/calipso
+++ b/docs/submodules/calipso
@@ -1 +1 @@
-Subproject commit 648a394f7a318443dfd82f790f83a79616c26905
+Subproject commit 2e47d8704fa0fe56ced38ddb4fc94f111079bd82