Update git submodules

* Update docs/submodules/snaps from branch 'master'
  - Sync requirements.txt with OpenStack (novaclient)

    It completes "Use neutron to create floating IPs" [1]

    [1] https://gerrit.opnfv.org/gerrit/#/c/36389/

    Change-Id: I11c591d86509fa41b4b0c4a7a758ff0ceed321c2
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>

diff --git a/docs/submodules/snaps b/docs/submodules/snaps
index e25472f..953c49e 160000 (submodule)
--- a/docs/submodules/snaps
+++ b/docs/submodules/snaps
@@ -1 +1 @@
-Subproject commit e25472fad7c7494f6ee71d8fd79f1410b9406844
+Subproject commit 953c49ee62d444c4c5f7f9c8d47c57e955129204