Update git submodules

Update git submodules

* Update docs/submodules/sdc/sdc-workflow-designer.git from branch 'master'
  to cdff1c49539736b0bf16c119ba158ff776a3d5c9
  - Migrate sdc-sdc-workflow-designer docs

    Merging this will create
    https://onap-sdc-sdc-workflow-designer.readthedocs.io
    This build will run in parallel
    to the current docs generation method
    until we are ready to cut over.

    Issue-ID: CIMAN-364
    Signed-off-by: Jessica Wagantall <jwagantall@linuxfoundation.org>
    Change-Id: I3f5d2ae1354045437581edac43865b7230724ec4