move loaders and webpack plugins from "dependencies" to "devDependencies"

We can group  necessary  dependencies to vendor for [Code Splitting - Libraries
](https://webpack.js.org/guides/code-splitting-libraries/)
```
const pkg = require('./package.json')

  entry: {
    app: [`${PATHS.src}/index.js`],
    style: PATHS.style,
    vendor: Object.keys(pkg.dependencies))
  },
```