Bump core-js from 3.1.3 to 3.4.1

Bumps [core-js](https://github.com/zloirock/core-js) from 3.1.3 to 3.4.1.
- [Release notes](https://github.com/zloirock/core-js/releases)
- [Changelog](https://github.com/zloirock/core-js/blob/master/CHANGELOG.md)
- [Commits](zloirock/core-js@v3.1.3...v3.4.1)

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

package.json

@@ -22,7 +22,7 @@
     "@angular/platform-browser-dynamic": "^6.1.10",
     "@angular/router": "^6.1.10",
     "angular2-uuid": "^1.1.1",
-    "core-js": "^3.1.3",
+    "core-js": "^3.4.1",
     "firebase": "^5.11.1",
     "rxjs": "^6.5.2",
     "zone.js": "^0.8.29"