Bump fs-extra from 7.0.1 to 8.1.0 in /app

Bumps [fs-extra](https://github.com/jprichardson/node-fs-extra) from 7.0.1 to 8.1.0.
- [Release notes](https://github.com/jprichardson/node-fs-extra/releases)
- [Changelog](https://github.com/jprichardson/node-fs-extra/blob/master/CHANGELOG.md)
- [Commits](https://github.com/jprichardson/node-fs-extra/compare/7.0.1...8.1.0)

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

app/package.json

@@ -19,7 +19,7 @@
     "electron-is-dev": "1.0.1",
     "electron-squirrel-startup": "1.0.0",
     "file-uri-to-path": "2.0.0",
-    "fs-extra": "7.0.1",
+    "fs-extra": "8.1.0",
     "git-describe": "4.0.4",
     "lodash": "4.17.15",
     "mkdirp": "0.5.1",

app/yarn.lock

@@ -209,11 +209,12 @@ find-up@^3.0.0:
   dependencies:
     locate-path "^3.0.0"
 
-fs-extra@7.0.1:
-  version "7.0.1"
-  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-7.0.1.tgz#4f189c44aa123b895f722804f55ea23eadc348e9"
+fs-extra@8.1.0:
+  version "8.1.0"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-8.1.0.tgz#49d43c45a88cd9677668cb7be1b46efdb8d2e1c0"
+  integrity sha512-yhlQgA6mnOJUKOsRUFsgJdQCvkKhcz8tlZG5HBQfReYZy46OwLcY+Zia0mtdHsOo9y/hP+CxMN0TU9QxoOtG4g==
   dependencies:
-    graceful-fs "^4.1.2"
+    graceful-fs "^4.2.0"
     jsonfile "^4.0.0"
     universalify "^0.1.0"
 
@@ -239,9 +240,10 @@ git-describe@4.0.4:
   optionalDependencies:
     semver "^5.6.0"
 
-graceful-fs@^4.1.2, graceful-fs@^4.1.6:
-  version "4.2.2"
-  resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.2.2.tgz#6f0952605d0140c1cfdb138ed005775b92d67b02"
+graceful-fs@^4.1.6, graceful-fs@^4.2.0:
+  version "4.2.3"
+  resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.2.3.tgz#4a12ff1b60376ef09862c2093edd908328be8423"
+  integrity sha512-a30VEBm4PEdx1dRB7MFK7BejejvCvBronbLjht+sHuGYj8PHs7M/5Z+rt5lw551vZ7yfTCj4Vuyy3mSJytDWRQ==
 
 iconv-lite@~0.4.13:
   version "0.4.24"