Bump @babel/preset-env from 7.1.0 to 7.1.6

Bumps [@babel/preset-env](https://github.com/babel/babel) from 7.1.0 to 7.1.6.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](babel/babel@v7.1.0...v7.1.6)

Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -39,7 +39,7 @@
   "license": "MPL-2.0",
   "dependencies": {
     "@babel/core": "^7.1.0",
-    "@babel/preset-env": "^7.1.0",
+    "@babel/preset-env": "^7.1.6",
     "@babel/preset-react": "^7.0.0",
     "autoprefixer": "^9.3.1",
     "babel-core": "^6.26.3",