fix(package): update commander to version 5.1.0

Closes #108

Author: greenkeeper[bot]

package.json

@@ -26,7 +26,7 @@
     "chokidar": "^1.6.0",
     "clone-stats": "^1.0.0",
     "colors": "^1.1.2",
-    "commander": "^2.9.0",
+    "commander": "^5.1.0",
     "connect-history-api-fallback": "^1.3.0",
     "consolidate": "^0.14.1",
     "css-loader": "^0.25.0",