fix(package): update mkdirp to version 1.0.4

Closes #128

Author: greenkeeper[bot]

package.json

@@ -50,7 +50,7 @@
     "commander": "^2.9.0",
     "cross-spawn": "^6.0.5",
     "debug": "^4.1.1",
-    "mkdirp": "^0.5.1",
+    "mkdirp": "^1.0.4",
     "q": "^1.5.1",
     "yeoman-environment": "^2.3.4"
   },