Update git submodules

* Update docs/submodules/yardstick from branch 'stable/fraser'
  - Merge "Remove unused methods in SampleVNF" into stable/fraser
  - Remove unused methods in SampleVNF

    The following private methods are unused in
    yardstick/network_services/vnf_generic/vnf/sample_vnf.py:SampleVNF

    * _build_ports(self)
    * _get_route_data(self, route_index, route_type)
    * _get_port0localip6(self)
    * _get_port1localip6(self)
    * _get_port0prefixlen6(self)
    * _get_port1prefixlen6(self)
    * _get_port0gateway6(self)
    * _get_port1gateway6(self)

    They are being removed as:
    * _get_port* functions are already implemented and used in MultiPortConfig
    * _get_route_data is an auxillary functions used by the previous ones
    * _build_ports is implemented in the helpers

    JIRA: YARDSTICK-1122
    Change-Id: Ie7a706cd87b610ea56f89214118a02e612a70dc0
    Signed-off-by: Emma Foley <emma.l.foley@intel.com>
    (cherry picked from commit 50bcd3e477bc29abb43ed73643d551ff55a73403)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index c8d64fa..5a05730 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit c8d64fa99dc51f5914bcbeb01a39eee5df7b4576
+Subproject commit 5a05730af35e6dfa5e623e3fa0a29c23ed704d71