Update git submodules

Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to cc16a3d5cca645bdfb8af177c85ab06efe97c27b
  - Merge "Make RKE the default cluster deployment tool"
  - Make RKE the default cluster deployment tool

    This change substitutes rancher_kubernetes.yml for
    rke.yml in site.yml making the RKE default deployment
    mechanism for kubernetes cluster.

    Change-Id: Ie1a0cb1eb94a3c5e8efd5c2c7e682c0292bc9152
    Issue-ID: OOM-1873
    Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>