Update NPM and Grunt

[cy2201]

Make sure these boxes are checked before submitting your issue.

• You are using this for WordPress.
• You have Divi installed.
• You have lint your code to ensure the problem isn't caused by your code.
• You have already searched the GitHub issues and it has not been reported before.

Hi, this repository wasn't updated since years. To make it easier for the community please update the packages for NPM / Grunt so we can start easily to develope websites. Otherwise a lot people have to update the npm package versions before they can start instead of one of your team updates this repo once. Thanks.

[cy2201]

Specifically, I have problems getting grunt up and running.

When I run grunt, I got: "Replace Autoprefixer browsers option to Browserslist config. Use browserslist key in package.json or .browserslistrc file."

What I already did:
npm update and npm install <package-name>@latest

npm install grunt-wakeup@latest

Then I added

  "browserslist": [
    "defaults",
    "not IE 11",
    "maintained node versions"
  ]

to package.json.

And I changed this

    postcss:
      dev:
        options:
          map: true,
          processors: [
            require('autoprefixer')({
              browsers: ['last 2 versions']
            })
          ]

        src: 'style.css'

      dist:
        options:
          map: false,
          processors: [
            require('autoprefixer')({
              browsers: ['last 6 versions']
            })
          ]

        src: 'style.css'

to

    postcss:
      dev:
        options:
          map: true,
          processors: [
            require('autoprefixer')()
          ]
        src: 'style.css'

      dist:
        options:
          map: false,
          processors: [
            require('autoprefixer')()
          ]
        src: 'style.css'

in Gruntfile.coffee.

I have no more errors but Autoprefixer doesn't do his job. I got a warning "Warning: [object Object] is not a PostCSS plugin Use --force to continue." It seems, my changes are not correct.

Can you help me or commit a new working version of this child theme?

Thanks.