chore(deps-dev): bump rollup from 1.15.3 to 1.15.6

Bumps [rollup](https://github.com/rollup/rollup) from 1.15.3 to 1.15.6.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v1.15.3...v1.15.6)

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

yarn.lock

@@ -3251,9 +3251,9 @@ rollup-pluginutils@^2.3.0:
     estree-walker "^0.6.1"
 
 rollup@^1.15.3:
-  version "1.15.3"
-  resolved "https://registry.yarnpkg.com/rollup/-/rollup-1.15.3.tgz#bb5875cf33eba5ef0fe3d6ed84b9e099ec94b3df"
-  integrity sha512-u2TVHLE/iUvFNAVSQb2DT6XEydOkgEHGLoRnY4jKJiZR/lmhqOM+ofGwSVbHhysZheAakqIa7B/3gChoK9VY0w==
+  version "1.15.6"
+  resolved "https://registry.yarnpkg.com/rollup/-/rollup-1.15.6.tgz#caf0ed28d2d78e3a59c1398e5a3695fb600a0ef0"
+  integrity sha512-s3Vn3QJQ5YVFfIG4nXoG9VdL1I37IZsft+4ZyeBhxE0df1kCFz9e+4bEAbR4mKH3pvBO9e9xjdxWPhhIp0r9ow==
   dependencies:
     "@types/estree" "0.0.39"
     "@types/node" "^12.0.8"