fix(package): update debug to version 4.0.1

Closes #9

Author: greenkeeper[bot]

package.json

@@ -24,7 +24,7 @@
     "test": "node-gyp rebuild --directory test && mocha -gc --reporter spec"
   },
   "dependencies": {
-    "debug": "^3.1.0"
+    "debug": "^4.0.1"
   },
   "devDependencies": {
     "bindings": "^1.3.0",