Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge "Support pre-Provisioned credentials"
  - Support pre-Provisioned credentials

    If USE_DYNAMIC_CREDENTIALS = False, Functest is expected for
    /home/opnfv/functest/data/accounts.yaml which contains the set of
    pre-existing credentials to use for testing [1].

    It also sets admin_domain_scope and default_credentials_domain_name.

    [1] https://docs.openstack.org/tempest/latest/configuration.html

    Change-Id: Ie7b81f0c56049260ca99b8e3a6d58cb8a2660659
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>