multiform.json

{
  "defaults": {
    "loose": true,
    "stage": 0
  },
  "builds": [
    {
      "version": "4.1.0.27",
      "options": {
        "blacklist": [
          "regenerator",
          "es6.forOf",
          "es6.templateLiterals",
          "es6.constants"
        ],
        "optional": [
          "bluebirdCoroutines"
        ]
      }
    },
    {
      "options": {
        "optional": [
          "runtime",
          "es7.asyncFunctions"
        ]
      }
    }
  ]
}