fix(package): update debug to version 4.1.0

Closes #26

Author: greenkeeper[bot]

package.json

@@ -70,7 +70,7 @@
   },
   "dependencies": {
     "bluebird": "3.5.0",
-    "debug": "2.6.8",
+    "debug": "4.1.0",
     "fsm-as-promised": "0.14.4",
     "lodash": "4.17.4"
   },