Update git submodules

Update git submodules

* Update docs/submodules/samplevnf from branch 'stable/fraser'
  - Adding support for Ubuntu 17.10...

    Change-Id: I9a9da79cb4ccb245ccb38b50b561da51a40a359d
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>
  - Adding centos.json to be used with packer to generate a VM with PROX

    Based on a CentOS cloud image downloadable from the web, you can now use
    packer to create an image that has DPDK and PROX installed in the
    proper directories. The VM is also tuned for guest VNFs.
    A service is also created to deal with the proper isolated_cpu settings
    for tuned. The service will also make sure uio and igb_uio are loaded.
    The prox_user_data.sh is not needed any more and hence deleted.
    ctrl-c of runrapid.py will now also stop prox in all the VMs so a new
    test can be started.

    Change-Id: I16cc59878e2d4912757f42e05f98d51dff5feb89
    Signed-off-by: Luc Provoost <luc.provoost@intel.com>
  - TempFix: vCGNAPT/vACL ipv4 perf issue

    Change-Id: I924fcac7a65c0d221d5d422f419deb9c0f864172
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>
  - Temp Fix for vFW perf issue

    Change-Id: I324fcac7a65c0d221d5d422f419deb9c0f864172
    Signed-off-by: Deepak S <deepak.s@linux.intel.com>