Update git submodules

Update git submodules

* Update docs/submodules/snaps from branch 'master'
  - Refactoring of SecurityGroupSettings to extend SecurityGroupConfig

    SecurityGroupSettings, SecurityGroupSettings and neutron_utils have a
    runtime cyclical dependency. This patch reduces this dependency and
    deprecates the SecurityGroupSettings and SecurityGroupRuleSettings class with
    snaps.config.security_group SecurityGroupConfig and SecurityGroupRuleConfg classes

    JIRA: SNAPS-224

    Change-Id: I6cd82ed5be31f4a24449be767b203e86489b1962
    Signed-off-by: spisarski <s.pisarski@cablelabs.com>