Update dependency serialize-to-js to v3 [SECURITY]

Author: renovate[bot]

amp-camp/package.json

@@ -30,7 +30,7 @@
     "jsdom": "^11.12.0",
     "mustache-express": "^1.3.0",
     "request": "^2.88.0",
-    "serialize-to-js": "^1.2.2",
+    "serialize-to-js": "^3.0.0",
     "through2": "^2.0.5",
     "uglify-es": "^3.3.10",
     "workbox-build": "^3.6.3",