Merge pull request #204 from ember-fastboot/greenkeeper/debug-4.1.0

fix(package): update debug to version 4.1.0

Author: kratiahuja

package.json

@@ -28,7 +28,8 @@
   "dependencies": {
     "chalk": "^2.0.1",
     "cookie": "^0.3.1",
-    "debug": "^3.0.0",
+    "debug": "^4.1.0",
+    "exists-sync": "0.0.4",
     "najax": "^1.0.2",
     "resolve": "^1.8.1",
     "rsvp": "^4.7.0",