Bump rollup from 0.63.4 to 2.66.1

Bumps [rollup](https://github.com/rollup/rollup) from 0.63.4 to 2.66.1.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v0.63.4...v2.66.1)

---
updated-dependencies:
- dependency-name: rollup
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

package.json

@@ -49,7 +49,7 @@
     "mocha": "^6.1.4",
     "native-promise-only": "^0.8.0-a",
     "nyc": "^14.1.1",
-    "rollup": "^0.63.4",
+    "rollup": "^2.66.1",
     "rollup-plugin-node-resolve": "^2.0.0",
     "rollup-plugin-npm": "^2.0.0",
     "rsvp": "^4.8.5",