Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to d9160c65acd59d9e844b1ca72e6da7c6ee30f1fc
  - Merge "switch to docker-maven-plugin because that's all"
  - switch to docker-maven-plugin because that's all
    
    switch to docker-maven-plugin because that's all we need
    
    Issue-ID: SO-2933
    Signed-off-by: Benjamin, Max (mb388a) <mb388a@att.com>
    Change-Id: I65783d3a7c172f4ce7fc39d64a3987eeae58feed
    
1 file changed