fix(package): update mkdirp to version 1.0.4

Closes #44

Author: greenkeeper[bot]

package.json

@@ -50,7 +50,7 @@
     "cli-prompt": "^0.6.0",
     "commander": "^2.8.1",
     "debug": "^2.6.8",
-    "mkdirp": "^0.5.1"
+    "mkdirp": "^1.0.4"
   },
   "devDependencies": {
     "bluebird": "^3.5.0",