Update git submodules

Update git submodules

* Update docs/submodules/snaps from branch 'master'
  - Merge "Created domain classes for security groups."
  - Created domain classes for security groups.

    Created SecurityGroup and SecurityGroupRule classes so the neutron_utils
    for security groups will be returning objects of these types instead of
    the OpenStack objects returned by the API calls.

    JIRA: SNAPS-116

    Change-Id: I76ed1f85f7d54b984fc6f6ac28cee7680a1109e5
    Signed-off-by: spisarski <s.pisarski@cablelabs.com>