fix(package): update fs-extra to version 8.1.0

Closes #11

Author: greenkeeper[bot]

package.json

@@ -41,7 +41,7 @@
   "dependencies": {
     "commander": "2.19.0",
     "dateformat": "3.0.3",
-    "fs-extra": "7.0.1",
+    "fs-extra": "8.1.0",
     "rc": "1.2.8",
     "slugify": "1.3.4"
   },