chore(package): update serve to version 9.0.0

Author: greenkeeper[bot]

package.json

@@ -29,7 +29,7 @@
     "karma-spec-reporter": "0.0.32",
     "karma-webpack": "^2.0.3",
     "phantomjs": "^2.1.7",
-    "serve": "^8.2.0",
+    "serve": "^9.0.0",
     "standard": "^10.0.2",
     "webpack": "^3.3.0"
   },