Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Rewrite TempestResourcesManager

    It now leverages on OpenStack Shade to allow gating OpenStack master
    as asked by TSC. Switching to OpenStack master (OpenStack SDK Rocky)
    requires to change only one line.

    It stops dedicating the network to the user possibly created because
    the support is incomplete (the users have to be registed in
    tempest.conf and the multiprocessing has to be enforced).

    It also writes the second image and the second flavor in tempest.conf.

    Change-Id: I9fe2c90a6073ebc240e9aa8fdf2ef93d5dd5f15f
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
  - Rewrite vping_ssh and vping_userdata

    They now leverage on shade to allow gating OpenStack master as asked
    by TSC. Switching to OpenStack master (openstacksdk) requires to
    change only one line.

    It deletes the related unit tests as they have to be fully rewritten.
    They will be added in another change.

    Change-Id: I0c60681d6e1c0944960770429ef972947dd85321
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
  - Set image_url as filename

    It will be reused as soon as vping switches to openstacksdk.

    Change-Id: Ib84f4b35b22ead1741579ec9140d3626f9102469
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>