chore(package): update rollup to version 1.15.0

Author: greenkeeper[bot]

package.json

@@ -39,7 +39,7 @@
     "eslint": "^5.10.0",
     "husky": "^2.3.0",
     "jsdom": "^15.1.0",
-    "rollup": "^1.12.3",
+    "rollup": "^1.15.0",
     "rollup-plugin-node-resolve": "^5.0.0",
     "rollup-plugin-terser": "^5.0.0",
     "tape": "^4.9.0",