Update git submodules

* Update docs/submodules/qtip from branch 'master'
  - Reorganize requirements

    - move test-requirements to ./requirements/test
    - freeze requirements in ./requirements/frozen{,-test}.txt
    - add necessary packages for requirements checking

    Change-Id: I451e75bd0d9654ab37940336145cf3b4d0e365fe
    Signed-off-by: Yujun Zhang <zhang.yujunz@zte.com.cn>

diff --git a/docs/submodules/qtip b/docs/submodules/qtip
index 7be99b4..9e4d243 160000 (submodule)
--- a/docs/submodules/qtip
+++ b/docs/submodules/qtip
@@ -1 +1 @@
-Subproject commit 7be99b40106a0c585f953f6506480a2524a7711a
+Subproject commit 9e4d243f1360158555fe92cc35fae6521bfdfce5