[chore] Bump debug to version 3.1.0

Author: darrachequesne

package.json

@@ -24,7 +24,7 @@
     "test": "nyc mocha --reporter spec --slow 200 --bail --timeout 10000 test/socket.io.js"
   },
   "dependencies": {
-    "debug": "~2.6.6",
+    "debug": "~3.1.0",
     "engine.io": "~3.1.0",
     "socket.io-adapter": "~1.1.0",
     "socket.io-client": "2.0.4",