chore(deps): update dependency rollup to v4

Author: renovate[bot]

package-lock.json

@@ -65,7 +65,7 @@
     "mocha": "5.2.0",
     "node-sass": "4.14.1",
     "prettier": "2.0.5",
-    "rollup": "2.59.0",
+    "rollup": "4.30.0",
     "rollup-plugin-filesize": "9.1.1",
     "rollup-plugin-istanbul": "2.0.1",
     "rollup-plugin-svelte": "5.2.3",