Update git submodules

* Update docs/submodules/qtip from branch 'master'
  - Merge "Rename docs/testing/developer/design to docs/testing/developer/devguide"
  - Rename docs/testing/developer/design to docs/testing/developer/devguide

    See https://git.opnfv.org/opnfvdocs/tree/docs/testing/testing-dev.rst

    Change-Id: Iac14adf4a2876fd74972dcf6279f7022e92cb9b5
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>

diff --git a/docs/submodules/qtip b/docs/submodules/qtip
index ebed515..218495e 160000 (submodule)
--- a/docs/submodules/qtip
+++ b/docs/submodules/qtip
@@ -1 +1 @@
-Subproject commit ebed51569f56d240d26d060e7cf7d6c502b5545d
+Subproject commit 218495e275178b93441390d17a12cb7b7e7f6112