fix(package): update debug to version 4.0.0

Author: greenkeeper[bot]

package.json

@@ -17,7 +17,7 @@
   ],
   "dependencies": {
     "@semantic-release/error": "^2.1.0",
-    "debug": "^3.1.0",
+    "debug": "^4.0.0",
     "execa": "^1.0.0",
     "lodash": "^4.17.4",
     "parse-json": "^4.0.0"