Update git submodules

* Update docs/submodules/qtip from branch 'master'
  - Some Optimizations

    - remove container and image without -f
    - remove duplicated code from verify_storage.sh, replaced by
    the script launch_containers_by_testsuite.sh
    - move the common sentences from periodic.sh to
    launch_containers_by_testsuite.sh
    - add 'QTIP' as prompt for print messages

    Change-Id: Ia9aa61a3b60c1049af3499a06f2c6cd0dc181552
    Signed-off-by: zhihui wu <wu.zhihui1@zte.com.cn>

diff --git a/docs/submodules/qtip b/docs/submodules/qtip
index a41a1dc..4bc87f5 160000 (submodule)
--- a/docs/submodules/qtip
+++ b/docs/submodules/qtip
@@ -1 +1 @@
-Subproject commit a41a1dc52e79a2f37d0572a5ed251492f414dc57
+Subproject commit 4bc87f5dc55cfbcc1cc7cdcbd1b6414d0da1e987