Update git submodules

* Update docs/submodules/so.git from branch 'master'
  to d6e85d547f5eac006b1da5d3b2ddc19daf8564da
  - Merge "added in graceful shutdown to spring boot"
  - added in graceful shutdown to spring boot

    added in graceful shutdown to spring boot
    updated the poms to include catalina and upped fabric
    added in eventlistener instead of application listener

    Issue-ID: SO-2655
    Signed-off-by: Benjamin, Max (mb388a) <mb388a@att.com>
    Change-Id: I2d8674cc82a9167604b2d38a49bffba42cee32ff