Update git submodules

Update git submodules

* Update docs/submodules/compass4nfv from branch 'master'
  - Upgrade OpenStack version from Ocata to Pike

    JIRA: COMPASS-565

    For OPNFV F release, it's going to use OpenStack Pike as the NFVI
    component. This task is created to monitor the upgrade work of
    OpenStack Pike. Subtasks as follow:
    - Add Pike related configurations to compass_conf
    - Upgrade ubuntu os to ubuntu 16.04.3
    - Upgrade centos os to centos 7.4
    - Upgrade openstack-ansible from ocata to pike
    - Upgrade openstack repos from ocata to pike

    Change-Id: I2202e8e3ae23dae8e575c89170c9e5e057757870
    Signed-off-by: Yifei Xue <xueyifei@huawei.com>