.babelrc

{
  "env": {
    "development": {
      "presets": [ "es2015", "stage-0" ]
    },
    "rollup": {
      "presets": [ "es2015-rollup", "stage-0"  ]
    },
    "jsnext": {
      "presets": [ ["es2015", { "modules": false }], "stage-0"  ]
    }
  }
}