ots/.babelrc

{
  "presets": [
    [
      "env",
      {
        "targets": {
          "browsers": [
            "last 3 versions",
            "Safari >= 10",
            "not ie <= 8",
            "Edge >= 12",
            "iOS >= 10",
            "Android >= 4.4"
          ]
        }
      }
    ],
    "minify"
  ]
}