fix(package): update fs-extra to version 7.0.0

Closes #16

Author: greenkeeper[bot]

package.json

@@ -28,7 +28,7 @@
   "homepage": "https://github.com/hax/semicolon-less.js",
   "dependencies": {
     "docopt": "^0.6.2",
-    "fs-extra": "^5.0.0",
+    "fs-extra": "^7.0.0",
     "isstream": "^0.1.1",
     "readable-stream": "^2.0.0",
     "semi": "^4.0.3"