fix(package): update debug to version 4.0.1

Closes webtorrent#289

Author: greenkeeper[bot]

package.json

@@ -24,7 +24,7 @@
     "bittorrent-peerid": "^1.0.2",
     "bn.js": "^4.4.0",
     "compact2string": "^1.2.0",
-    "debug": "^3.1.0",
+    "debug": "^4.0.1",
     "inherits": "^2.0.1",
     "ip": "^1.0.1",
     "lru": "^3.0.0",