Update git submodules

Update git submodules

* Update docs/submodules/snaps from branch 'master'
  - Merge "Fixed potential problems with image creation exceptions."
  - Fixed potential problems with image creation exceptions.

    With Glance client v2, it appears that rolling back on image
    creation error was sending in an OpenStack image object into
    the delete_image() function where it should have been expecting
    a SNAPS-OO Image domain object.
    Also added log messages to help expose other potential issues
    if this patch does not address the root problem at hand.

    JIRA: SNAPS-139

    Change-Id: I52591ff1d055ddf4eacbbc49b3bc8718285edcfa
    Signed-off-by: spisarski <s.pisarski@cablelabs.com>