Update git submodules

Update git submodules

* Update docs/submodules/yardstick from branch 'master'
  - temp unblock unittests

    ======================================================================
    ERROR: common.test_packages (unittest.loader._FailedTest)
    ----------------------------------------------------------------------
    ImportError: Failed to import test module: common.test_packages
    Traceback (most recent call last):
      File "/usr/lib/python3.5/unittest/loader.py", line 428, in _find_test_path
        module = self._get_module_from_name(name)
      File "/usr/lib/python3.5/unittest/loader.py", line 369, in _get_module_from_name
        __import__(name)
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/yardstick/tests/unit/common/test_packages.py", line 17, in <module>
        from pip.operations import freeze
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/__init__.py", line 45, in <module>
        from pip.vcs import git, mercurial, subversion, bazaar  # noqa
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/vcs/mercurial.py", line 9, in <module>
        from pip.download import path_to_url
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/download.py", line 40, in <module>
        from pip._vendor import requests, six
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/_vendor/requests/__init__.py", line 98, in <module>
        from . import packages
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/_vendor/requests/packages.py", line 12, in <module>
        sys.modules['pip._vendor.requests.packages.' + mod] = sys.modules["pip._vendor." + mod]
    KeyError: 'pip._vendor.urllib3.contrib'

     File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/yardstick/tests/unit/common/test_packages.py", line 16, in <module>
        from pip import exceptions as pip_exceptions

    ======================================================================
    ERROR: common.test_packages (unittest.loader._FailedTest)
    ----------------------------------------------------------------------
    ImportError: Failed to import test module: common.test_packages
    Traceback (most recent call last):
      File "/usr/lib/python3.5/unittest/loader.py", line 428, in _find_test_path
        module = self._get_module_from_name(name)
      File "/usr/lib/python3.5/unittest/loader.py", line 369, in _get_module_from_name
        __import__(name)
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/yardstick/tests/unit/common/test_packages.py", line 16, in <module>
        from pip import exceptions as pip_exceptions
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/__init__.py", line 45, in <module>
        from pip.vcs import git, mercurial, subversion, bazaar  # noqa
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/vcs/mercurial.py", line 9, in <module>
        from pip.download import path_to_url
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/download.py", line 40, in <module>
        from pip._vendor import requests, six
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/_vendor/requests/__init__.py", line 98, in <module>
        from . import packages
      File "/home/jenkins/opnfv/slave_root/workspace/yardstick-verify-master/.tox/py3/lib/python3.5/site-packages/pip/_vendor/requests/packages.py", line 12, in <module>
        sys.modules['pip._vendor.requests.packages.' + mod] = sys.modules["pip._vendor." + mod]
    KeyError: 'pip._vendor.urllib3.packages.backports.makefile'

    Change-Id: I43b1edc23cebe0db97b6b56a551acd376986dfea
    Signed-off-by: Ross Brattain <ross.b.brattain@intel.com>