message: add volume-server npm start script
diff: "serve": "http-server -p 1338",
  "model-server": "node lib/servers/model/server.js",
  "model-server-watch": "nodemon --watch lib lib/servers/model/server.js",
  + "volume-server": "node lib/servers/volume/server.js --idMap em 'test/${id}.mdb' --defaultPort 1336",
  "preversion": "npm run test",
  "postversion": "git push && git push --tags",
  "prepublishOnly": "npm run test && npm run build"
  