Update git submodules

* Update docs/submodules/yardstick from branch 'stable/fraser'
  - Merge "Add "os_cloud_config" as a new context flag parameter" into stable/fraser
  - Add "os_cloud_config" as a new context flag parameter

    This new parameter will contain the OpenStack cloud specific configuration
    used by Shade client. This new flag is used only in Heat context.

    By default, this new parameter (dict) will contain this content:
      'os_cloud_config': {'verify': False}

    This field will be used by HeatStack [1] to create a Shade cloud. Shade
    retrieves, if not defined, the OpenStack configuration from
    "os_client_config". This configuration is used to generate the cloud
    configuration, which is the description of the OpenStackCloud returned.

    The default parameter defined, "verify", refers to the related bug. By
    default, in case of using SSL certificate it will not be verified.

    [1] https://github.com/opnfv/yardstick/blob/b338d3091bb0beb89d4ad9f7c144f43a31a19a74/yardstick/orchestrator/heat.py#L47

    JIRA: YARDSTICK-1139

    Change-Id: I875a7018401b84e51dab775b8194174645d27e06
    Signed-off-by: Rodolfo Alonso Hernandez <rodolfo.alonso.hernandez@intel.com>
    (cherry picked from commit 9ae331e1aa1081c3e821512d1940846dfb4063ec)

diff --git a/docs/submodules/yardstick b/docs/submodules/yardstick
index 70ea01b..931c7d8 160000 (submodule)
--- a/docs/submodules/yardstick
+++ b/docs/submodules/yardstick
@@ -1 +1 @@
-Subproject commit 70ea01b882a5ff61a36f8927d64d1bf3b9446838
+Subproject commit 931c7d87597fd61f9e300be2637a0bdd485001d9