casper/renovate.json

{
  "extends": [
    "config:base"
  ],
  "packageRules": [
    {
      "packagePatterns": ["^postcss", "css", "autoprefixer"],
      "groupName": "css processors"
    },
    {
      "packagePatterns": ["gulp"],
      "groupName": "gulp"
    }
  ]
}