Refs #10218.  Made change to gsas data format.

On branch feature/10218_gsas_vulcan_format
Changes to be committed:

      modified:   ../Mantid/Framework/PythonInterface/plugins/algorithms/SaveVulcanGSS.py
Fixed doc test. Refs #10218.

On branch feature/10218_gsas_vulcan_format
Changes to be committed:

      modified:   Mantid/docs/source/algorithms/SaveVulcanGSS-v1.rst
Merge remote-tracking branch 'origin/feature/10218_gsas_vulcan_format'