Update git submodules

* Update docs/submodules/daisy from branch 'master'
  - Nomination of Committer promotion for Ya Zhou

    I'd like to nominate Ya Zhou(IRC name 'zhouya') for Daisy4NFV
    core reviewer.

    Ya started to work on Daisy4NFV since the beginning of the project
    and he has made significant contribution to project during E
    release cycle including adding support of deploying Ceph, Cinder,
    ODL and etc... [1][2]

    I have had a talked with him offline and he expressed willing to
    contribute more to Daisy4NFV project and I believe he will make a
    great addition to the core review team.

    All Daisy4NFV committers, please vote +1 or +2 if you support this
    nomination [3].

    [1] http://stackalytics.com/?project_type=opnfv-group&metric=commits&release=all&module=daisy
    [2] https://gerrit.opnfv.org/gerrit/#/q/owner:zhou.ya%2540zte.com.cn+status:merged+project:daisy
    [3] https://wiki.opnfv.org/display/DEV/Committer+Promotions

    Change-Id: I479ee737781d2692ef68edf3d86cb11a6ae0428f
    Signed-off-by: Zhijiang Hu <hu.zhijiang@zte.com.cn>

diff --git a/docs/submodules/daisy b/docs/submodules/daisy
index c9ddb92..2ce15da 160000 (submodule)
--- a/docs/submodules/daisy
+++ b/docs/submodules/daisy
@@ -1 +1 @@
-Subproject commit c9ddb929138a39ee22be8433074416575346734b
+Subproject commit 2ce15da683b2fbf9cdac71f49adb6f739442ed90