Bump rollup from 0.68.2 to 1.20.3

Bumps [rollup](https://github.com/rollup/rollup) from 0.68.2 to 1.20.3.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v0.68.2...v1.20.3)

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

Author: dependabot-preview[bot]

package-lock.json

@@ -40,7 +40,7 @@
     "react": "^16.9.0",
     "react-dom": "^16.9.0",
     "rimraf": "^2.6.3",
-    "rollup": "^0.68.2",
+    "rollup": "^1.20.3",
     "rollup-plugin-babel": "^3.0.7",
     "rollup-plugin-commonjs": "^9.3.4",
     "rollup-plugin-node-resolve": "^3.4.0",