Update dependency rollup to v0.66.6 (#83)

Author: renovate-bot

package-lock.json

@@ -42,7 +42,7 @@
     "lint-staged": "7.3.0",
     "prettier": "1.14.3",
     "rimraf": "2.6.2",
-    "rollup": "0.66.5",
+    "rollup": "0.66.6",
     "tslint": "5.11.0",
     "typescript": "3.1.1"
   },