chore(package): update rollup to version 2.11.1

Closes #44

Author: greenkeeper[bot]

package.json

@@ -114,7 +114,7 @@
     "prompt": "^1.0.0",
     "replace-in-file": "^4.0.0",
     "rimraf": "^2.6.2",
-    "rollup": "^1.1.2",
+    "rollup": "^2.11.1",
     "rollup-plugin-commonjs": "^10.0.0",
     "rollup-plugin-json": "^4.0.0",
     "rollup-plugin-node-resolve": "^4.0.0",