Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - Merge "Bump requirements to match OpenStack Queens release upper requirements"
  - Bump requirements to match OpenStack Queens release upper requirements

    tox -e os-requiremnts results:
    Validating requirements file "requirements.txt"
    Package "oslo.config" version 4.11.1 outdated, minimum version 5.1.0
    Package "keystoneauth1" version 3.1.0 outdated, minimum version 3.3.0
    Package "python-cinderclient" version 3.1.0 outdated, minimum version 3.3.0
    Package "requests" version 2.11.1 outdated, minimum version 2.14.2
    Package "osc-lib" version 1.7.0 outdated, minimum version 1.8.0
    Package "oslo.utils" version 3.28.0 outdated, minimum version 3.33.0
    Package "oslo.privsep" version 1.22.1 outdated, minimum version 1.23.0
    Incompatible requirement found!

    JIRA: YARDSTICK-1283

    Change-Id: I362c1e2b5c61abf09810ce2a2fe6bab39097d017
    Signed-off-by: rexlee8776 <limingjiang@huawei.com>