Update git submodules

Update git submodules

* Update docs/submodules/functest from branch 'master'
  - Merge changes I4079fa36,I3ad7a38e

    * changes:
      Allow refs as vnf requirement versions
      Avoid downloading git history

  - Allow refs as vnf requirement versions

    Change-Id: I4079fa3641373eee40f8a876a2a525635f2752eb
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>
  - Avoid downloading git history

    It decreases container build duration.
    depth 1 is set only when TAG is not a commit id because
    github.com doesn't advertise commit ids.

    It switches to git.openstack.org as much as possible.

    Change-Id: I3ad7a38eda0f7023302d71bb55de23828120f599
    Signed-off-by: Cédric Ollivier <cedric.ollivier@orange.com>