Upgrade commander to version 6

Author: realityking

package.json

@@ -44,7 +44,7 @@
   },
   "dependencies": {
     "chalk": "^4.1.0",
-    "commander": "^5.1.0",
+    "commander": "^6.2.1",
     "commondir": "^1.0.1",
     "debug": "^4.0.1",
     "dependency-tree": "^8.0.0",