chore: update rollup to 0.66.6

Author: xidedix

package.json

@@ -97,7 +97,7 @@
     "npm-run-all": "^4.1.3",
     "postcss-cli": "^6.0.0",
     "rimraf": "^2.6.2",
-    "rollup": "^0.66.5",
+    "rollup": "^0.66.6",
     "rollup-plugin-babel": "^4.0.3",
     "rollup-plugin-node-resolve": "^3.4.0",
     "semver": "^5.5.1",