message: fix dev script in package.json
diff: "prebuild": "npm run rebuild && npm run browserify-preload",
  "browserify-preload": "browserify -o js/preload/_preloadMain.js -x electron --insert-global-vars=__filename,__dirname js/preload/preloadMain.js --exclude electron-spellchecker",
  "rebuild": "electron-rebuild -f",
  - "dev": "npm run prebuild && && npm run set-dev-env && electron .",
  + "dev": "npm run prebuild && npm run set-dev-env && electron .",
  "test": "npm run lint && npm rebuild --build-from-source && cross-env ELECTRON_QA=true jest --config tests/jest_unit.json --runInBand && npm run rebuild",
  "spectron-test": "npm run lint && npm rebuild --build-from-source robotjs && cross-env ELECTRON_QA=true jest --config tests/spectron/jest_spectron.json --runInBand && npm run rebuild",
  "demo-win": "npm run prebuild && cross-env ELECTRON_DEV=true electron . --url=file:///demo/index.html",
  