Bump @babel/preset-env from 7.6.0 to 7.6.3

Bumps [@babel/preset-env](https://github.com/babel/babel) from 7.6.0 to 7.6.3.
- [Release notes](https://github.com/babel/babel/releases)
- [Changelog](https://github.com/babel/babel/blob/master/CHANGELOG.md)
- [Commits](babel/babel@v7.6.0...v7.6.3)

Signed-off-by: dependabot-preview[bot] <[email protected]>

Author: dependabot-preview[bot]

package-lock.json

@@ -44,7 +44,7 @@
     "@babel/generator": "7.6.2",
     "@babel/plugin-proposal-class-properties": "7.5.5",
     "@babel/plugin-proposal-object-rest-spread": "7.6.2",
-    "@babel/preset-env": "7.6.0",
+    "@babel/preset-env": "7.6.3",
     "@babel/preset-react": "7.0.0",
     "babel-plugin-relay": "5.0.0",
     "bintrees": "1.0.2",