{
  "name": "md-editor",
  "version": "0.0.1",
  "description": "",
  "main": "nwapp/index.html",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "nwbuild  -p 'osx64' ./ -o ./build"
  },
  "author": "Satoshi Watanabe",
  "license": "MIT",
  "devDependencies": {
    "gulp": "3.9.1",
    "gulp-util": "3.0.8",
    "node-webkit-builder": "1.0.13"
  }
}

{
  "name": "md-editor",
  "version": "0.0.1",
  "description": "",
  "main": "nwapp/index.html",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "build": "nwbuild  -p 'osx64' ./ -o ./build"
  },
  "author": "Satoshi Watanabe",
  "license": "MIT",
  "devDependencies": {
    "gulp": "4.0.2",
    "gulp-util": "3.0.8",
    "node-webkit-builder": "1.0.13"
  }
}

Update dependency gulp to v4
Update dependency gulp to v4
