Merge pull request #3 from Halceyon/greenkeeper/rollup-0.57.0

Update rollup to the latest version 🚀

Author: Halceyon

package.json

@@ -56,7 +56,7 @@
     "json-stable-stringify": "^1.0.1",
     "mocha": "^5.0.4",
     "parse-json": "^4.0.0",
-    "rollup": "^0.56.5",
+    "rollup": "^0.57.0",
     "rollup-plugin-babel": "^3.0.3",
     "semantic-release": "^12.4.1",
     "sinon": "^5.0.0",