fix(package): update debug to version 4.0.1

Closes #53

Author: greenkeeper[bot]

package.json

@@ -20,7 +20,7 @@
     "node": ">= 4.0"
   },
   "dependencies": {
-    "debug": "2.6.6",
+    "debug": "4.0.1",
     "got": "6.7.1",
     "is-url": "1.2.2",
     "micromatch": "2.3.11",