Update @types/fs-extra requirement from ^7.0.0 to ^8.0.0 (#99)

Updates the requirements on [@types/fs-extra](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/fs-extra) to permit the latest version.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/fs-extra)

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

Co-authored-by: null <27856297+dependabot-preview[bot]@users.noreply.github.com>

packages/formatjs/package.json

@@ -34,7 +34,7 @@
     "@types/babel__core": "^7.1.2",
     "@types/benchmark": "^1.0.31",
     "@types/chai": "^4.1.7",
-    "@types/fs-extra": "^7.0.0",
+    "@types/fs-extra": "^8.0.0",
     "@types/jest": "^24.0.15",
     "@types/mocha": "^5.2.7",
     "babel-jest": "^24.8.0",