Update git submodules

* Update docs/submodules/nfvbench from branch 'master'
  - Move docker container to tag 1.2.7

    Change-Id: I556204e6d64b3b71402f65ba3cc1b63e3969e0ca
    Signed-off-by: ahothan <ahothan@cisco.com>

diff --git a/docs/submodules/nfvbench b/docs/submodules/nfvbench
index f07e562..ca7bc60 160000 (submodule)
--- a/docs/submodules/nfvbench
+++ b/docs/submodules/nfvbench
@@ -1 +1 @@
-Subproject commit f07e562c36549f45b643d730de3990b0f850bfe0
+Subproject commit ca7bc608e72076dba0b9db50b473ab0d0d18c0e6