chore(package): update rollup-plugin-babel to version 2.6.0

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -32,7 +32,7 @@
     "babel": "^6.5.2",
     "babel-preset-es2015-rollup": "^1.1.1",
     "rollup": "^0.32.2",
-    "rollup-plugin-babel": "^2.4.0",
+    "rollup-plugin-babel": "^2.6.0",
     "rollup-plugin-commonjs": "^3.0.0",
     "rollup-plugin-node-resolve": "^1.5.0"
   }