npm scripts as a build tool

package.json

{
  "scripts": {
    "clean": "rm -f resources/css/style.css",
    "autoprefixer": "postcss -u autoprefixer -r resources/css/style.css",
    "scss": "node-sass --output-style compressed --source-map true resources/sass/PPP.scss resources/css/style.css",
    "serve": "browser-sync start --proxy 'ping.dev' --files 'resources/css/*.css, resources/images/*'",
    "build:css": "npm run scss && npm run autoprefixer",
    "build": "npm run build:css",
    "watch:css": "onchange 'resources/sass/*.scss' -- npm run build:css",
    "start": "npm-run-all -p serve watch:css",
    "postinstall": "npm run watch:all"
  },
  "keywords": [
    "autoprefixer",
    "node-sass",
    "postcss",
    "browser-sync",
    "onchange"
  ],
  "devDependencies": {
    "autoprefixer": "^6.3.3",
    "browser-sync": "^2.11.1",
    "cz-conventional-changelog": "^1.1.5",
    "eslint": "^2.2.0",
    "imagemin-cli": "^2.1.0",
    "merge-stream": "^1.0.0",
    "node-sass": "^3.4.2",
    "npm-run-all": "^1.5.1",
    "onchange": "^2.0.0",
    "postcss-cli": "^2.5.1",
    "svg-sprite-generator": "0.0.7",
    "svgo": "^0.6.1",
    "uglify-js": "^2.6.2"
  }
}