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

Author: greenkeeper[bot]

package.json

@@ -22,7 +22,7 @@
     "dir-glob": "^2.0.0",
     "escape-string-regexp": "^2.0.0",
     "form-data": "^2.3.3",
-    "fs-extra": "^7.0.1",
+    "fs-extra": "^8.0.0",
     "globby": "^9.0.0",
     "got": "^9.1.0",
     "lodash": "^4.17.11",