Upgrade rollup

Author: muan

package-lock.json

@@ -39,7 +39,7 @@
     "karma-mocha": "^2.0.1",
     "karma-mocha-reporter": "^2.2.5",
     "mocha": "^6.2.3",
-    "rollup": "^1.32.1",
+    "rollup": "^2.12.0",
     "rollup-plugin-node-resolve": "^5.2.0",
     "typescript": "^3.9.3"
   },