chore(package): update gzip-size to version 5.0.0

Author: greenkeeper[bot]

package.json

@@ -50,7 +50,7 @@
     "enzyme": "^3.3.0",
     "enzyme-adapter-react-16": "^1.1.1",
     "greenkeeper-lockfile": "^1.15.1",
-    "gzip-size": "^4.1.0",
+    "gzip-size": "^5.0.0",
     "jest": "^22.4.2",
     "jest-enzyme": "^6.0.0",
     "jsdom": "^11.6.2",