⬆️ Update rollup requirement from ^0.63.4 to ^0.67.4

Updates the requirements on [rollup](https://github.com/rollup/rollup) to permit the latest version.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](https://github.com/rollup/rollup/commits)

Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -41,7 +41,7 @@
   "devDependencies": {
     "chai": "^4.1.2",
     "holding": "^3.0.3",
-    "rollup": "^0.63.4",
+    "rollup": "^0.67.4",
     "fs-extra": "^7.0.0",
     "superagent": "^3.8.3"
   },