message: Only Babel for certain browsers (and not old Safari which doesn't support IndexedDB)
diff: ["env", {
  "targets": {
  "browsers": [
  - "last 2 versions"
  + "last 2 Chrome versions",
  + "last 2 ChromeAndroid versions",
  + "last 2 Firefox versions",
  + "last 1 Safari versions",
  + "last 1 iOS versions",
  + "last 2 Edge versions"
  ]
  },
  "modules": false,
  