Update to support Cromwell tasks and structs dependencies via zip file

[TomGardner]

Cromwell supports imports from sub-directories tasks and structs via a zip file.
This issue is for an enhancement to support this functionality.

Update to Dockerfile could be similar to:
COPY dependencies.zip /wdl_runner

Update to wdl_runner.sh could be similar to:
`

Execute the wdl_runner

python -u wdl_runner.py
--wdl wf.wdl
--workflow-inputs wf.inputs.json
--working-dir "${WORKSPACE}"
--workflow-options wf.options.json
--workflow-dependencies dependencies.zip
--output-dir "${OUTPUTS}"`

Update to wdl_runner.py (main) could be similar to:
parser.add_argument('--workflow-dependencies', required=False, help='The workflow dependencies (ZIP) file')

And (run):
`

Submit the job to the local Cromwell server

    (result, metadata) = self.driver.submit(self.args.wdl,
                                            self.args.workflow_inputs,
                                            self.args.workflow_options,
                                            self.args.workflow_dependencies)`

[hisplan]

Has this been implemented into wdl_runner?

[TomGardner]

Hi. Sorry I closed this by mistake. I don't know if this has been implemented yet. Re-opened.