Update dependency grunt-cli to v1

Author: renovate-bot

plugin/multiplex/package.json

@@ -11,7 +11,7 @@
   },
   "dependencies": {
     "express": "~4.13.3",
-    "grunt-cli": "~0.1.13",
+    "grunt-cli": "1.4.3",
     "mustache": "~2.2.1",
     "socket.io": "~1.3.7"
   },