Bump mock-fs from 4.10.4 to 4.12.0

Bumps [mock-fs](https://github.com/tschaub/mock-fs) from 4.10.4 to 4.12.0.
- [Release notes](https://github.com/tschaub/mock-fs/releases)
- [Changelog](https://github.com/tschaub/mock-fs/blob/master/changelog.md)
- [Commits](tschaub/mock-fs@v4.10.4...v4.12.0)

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

package.json

@@ -43,7 +43,7 @@
     "husky": "4.2.1",
     "jest": "^24.8.0",
     "lint-staged": "10.0.7",
-    "mock-fs": "4.10.4",
+    "mock-fs": "4.12.0",
     "prettier": "1.19.1"
   },
   "husky": {