Update git submodules

Update git submodules

* Update docs/submodules/releng from branch 'master'
  - Merge "prototypes: xci: Make sure Ansible dependencies are installed"
  - prototypes: xci: Make sure Ansible dependencies are installed

    'pip install ansible' is not enough on newly installed hosts which may
    lack the necessary build tools to install Ansible's dependencies. As
    such, we add a script similar to the bifrost/scripts/install-deps.sh
    one to pull in all the necessary distro-specific packages so Ansible
    and it's dependencies can be installed from scratch.

    Change-Id: I4b1e74644db9ace451ad763e4c54f1a3a43214fd