chore(package): update rollup to version 0.42.0 (#154)

Author: greenkeeper[bot]

package.json

@@ -54,7 +54,7 @@
     "mocha": "^3.1.2",
     "nyc": "^11.0.2",
     "promises-aplus-tests": "^2.1.1",
-    "rollup": "^0.41.6",
+    "rollup": "^0.42.0",
     "rollup-plugin-buble": "^0.15.0",
     "rollup-plugin-commonjs": "^8.0.2",
     "rollup-plugin-node-resolve": "^3.0.0",