Update git submodules

Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to 6864971d1fec3e58a7581b38a75c6bed6f390f4f
  - Merge "vnr vrf fk issue"
  - vnr vrf fk issue

    Updated flyway migration script to rename object as per review
    comments. Used Tosca node type for determining VRF and VNF nodes
    updated code based on review comments for schema.sql
    Altered ConfigurationCustomizationResource for VRF-VNF to have
    bidirectional relationship
    ToscaResourceInstaller ConfigurationResourceCustomization was made
    bidrectional

    Change-Id: Ib45151ff7a40edca38d512ae76f8889b1cc4d0c4
    Issue-ID: SO-1777
    Signed-off-by: Benjamin, Max (mb388a) <mb388a@us.att.com>