Update git submodules

Update git submodules

* Update docs/submodules/snaps from branch 'master'
  - Merge "Added method to return OpenStackVmInstance from Heat."
  - Added method to return OpenStackVmInstance from Heat.

    OpenStackHeatStack now can introspect the VMs that the template
    was responsible for deploying and return an instanitated instance
    of OpenStackVmInstance for each VM deployed. When the VM has a
    Floating IP, these instances have the ability to connect via
    SSH just like one created from scratch.

    JIRA: SNAPS-172

    Change-Id: I5a7ed3a09bb871afc55c718aa80a9069b1eb4da7
    Signed-off-by: spisarski <s.pisarski@cablelabs.com>