Bump rollup from 1.27.14 to 1.28.0

Bumps [rollup](https://github.com/rollup/rollup) from 1.27.14 to 1.28.0.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v1.27.14...v1.28.0)

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

package.json

@@ -129,7 +129,7 @@
     "npm-run-all": "^4.1.5",
     "popper.js": "^1.16.0",
     "postcss-cli": "^6.1.3",
-    "rollup": "^1.27.14",
+    "rollup": "^1.28.0",
     "rollup-plugin-babel": "^4.3.3",
     "rollup-plugin-istanbul": "^2.0.1",
     "serve": "^11.3.0",