chore(package): update rollup-plugin-babel to version 4.0.1

Closes #57

Author: greenkeeper[bot]

package.json

@@ -47,7 +47,7 @@
     "lodash.clonedeep": "^4.5.0",
     "parse5": "^4.0.0",
     "rollup": "^0.61.1",
-    "rollup-plugin-babel": "^3.0.2",
+    "rollup-plugin-babel": "^4.0.1",
     "rollup-plugin-commonjs": "^9.1.0",
     "rollup-plugin-node-builtins": "^2.1.2",
     "rollup-plugin-node-resolve": "^3.3.0",