chore(package): update fs-extra to version 8.0.0

Closes #71

Author: greenkeeper[bot]

package.json

@@ -93,7 +93,7 @@
     "eslint-plugin-jsx-a11y": "^6.0.3",
     "eslint-plugin-react": "^7.7.0",
     "file-loader": "^1.1.10",
-    "fs-extra": "^5.0.0",
+    "fs-extra": "^8.0.0",
     "gh-pages": "^1.1.0",
     "git-prepush-hook": "^1.0.2",
     "jest": "^22.4.2",