chore(package): update rollup to version 0.67.0

Author: greenkeeper[bot]

package.json

@@ -51,7 +51,7 @@
     "karma-mocha": "^1.3.0",
     "karma-mocha-reporter": "^2.2.5",
     "mocha": "^5.2.0",
-    "rollup": "^0.66.6",
+    "rollup": "^0.67.0",
     "rollup-plugin-babel": "^3.0.3",
     "rollup-plugin-commonjs": "^9.2.0",
     "rollup-plugin-node-resolve": "^3.4.0",