Update git submodules

* Update docs/submodules/daisy from branch 'master'
  - Switch master branch to openstack pike

    According to the patch in upstream [1].

    [1] https://review.openstack.org/#/c/514548/

    Change-Id: Ie8edee057aa46ffe0c3f4d96f0c9afb4f1635920
    Signed-off-by: Alex Yang <yangyang1@zte.com.cn>

diff --git a/docs/submodules/daisy b/docs/submodules/daisy
index 44114e6..8c42ba2 160000 (submodule)
--- a/docs/submodules/daisy
+++ b/docs/submodules/daisy
@@ -1 +1 @@
-Subproject commit 44114e67184078443f2c9f14353dd29dde7349cd
+Subproject commit 8c42ba2367f5197dbb158d5f50b89b332b484d75