chore(package): update babel-preset-es2015-rollup to version 1.2.0 (#35)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -30,7 +30,7 @@
   },
   "devDependencies": {
     "babel": "^6.5.2",
-    "babel-preset-es2015-rollup": "^1.1.1",
+    "babel-preset-es2015-rollup": "^1.2.0",
     "rollup": "^0.34.9",
     "rollup-plugin-babel": "^2.6.0",
     "rollup-plugin-commonjs": "^3.3.1",