chore(package): update rollup to version 2.11.0

Closes #53

Author: greenkeeper[bot]

package.json

@@ -38,7 +38,7 @@
     "mochawesome": "^3.0.2",
 
     "nyc": "^13.2.0",
-    "rollup": "^1.0.0",
+    "rollup": "^2.11.0",
     "rollup-plugin-node-resolve": "^5.0.0",
     "shelljs-release": "^0.3.0",
     "uglify-js": "^3.4.5"