Bump fs-extra from 7.0.1 to 8.0.1

Bumps [fs-extra](https://github.com/jprichardson/node-fs-extra) from 7.0.1 to 8.0.1.
- [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/commits)

package.json

@@ -48,7 +48,7 @@
     "cssnano": "^4.0.4",
     "find-up": "^3.0.0",
     "flat-cache": "^2.0.1",
-    "fs-extra": "^7.0.0",
+    "fs-extra": "^8.0.1",
     "glob": "^7.1.2",
     "highlight.js": "^9.15.6",
     "html-minifier": "^3.5.19",

yarn.lock

@@ -2171,6 +2171,14 @@ fs-extra@^7.0.0, fs-extra@^7.0.1:
     jsonfile "^4.0.0"
     universalify "^0.1.0"
 
+fs-extra@^8.0.1:
+  version "8.0.1"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-8.0.1.tgz#90294081f978b1f182f347a440a209154344285b"
+  dependencies:
+    graceful-fs "^4.1.2"
+    jsonfile "^4.0.0"
+    universalify "^0.1.0"
+
 fs-minipass@^1.2.5:
   version "1.2.5"
   resolved "https://registry.yarnpkg.com/fs-minipass/-/fs-minipass-1.2.5.tgz#06c277218454ec288df77ada54a03b8702aacb9d"