Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "testapi: bugfix of tox"
  - testapi: bugfix of tox

    error log

    https://gerrit.opnfv.org/gerrit/#/c/37053/
    https://build.opnfv.org/ci/job/testapi-verify-master/220/console

    Change-Id: Id278edad06c2852c662392d75fd3cf4041b03451
    Signed-off-by: MatthewLi <lijun_1203@126.com>

diff --git a/docs/submodules/releng b/docs/submodules/releng
index 57acae9..f057556 160000 (submodule)
--- a/docs/submodules/releng
+++ b/docs/submodules/releng
@@ -1 +1 @@
-Subproject commit 57acae96d4f574d3ba4a3f2d49faa972d13666d2
+Subproject commit f05755626655aa5532650823f869b513d4b5cd45