chore(deps-dev): bump rollup from 2.20.0 to 2.21.0

Bumps [rollup](https://github.com/rollup/rollup) from 2.20.0 to 2.21.0.
- [Release notes](https://github.com/rollup/rollup/releases)
- [Changelog](https://github.com/rollup/rollup/blob/master/CHANGELOG.md)
- [Commits](rollup/rollup@v2.20.0...v2.21.0)

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

package.json

@@ -62,7 +62,7 @@
     "jest-serializer-vue": "^2.0.2",
     "minimist": "^1.2.5",
     "prettier": "^2.0.5",
-    "rollup": "^2.20.0",
+    "rollup": "^2.21.0",
     "rollup-plugin-buble": "^0.19.8",
     "rollup-plugin-commonjs": "^10.1.0",
     "rollup-plugin-replace": "^2.2.0",

yarn.lock

@@ -6956,10 +6956,10 @@ rollup-pluginutils@^2.3.3, rollup-pluginutils@^2.5.0, rollup-pluginutils@^2.6.0,
   dependencies:
     estree-walker "^0.6.1"
 
-rollup@^2.20.0:
-  version "2.20.0"
-  resolved "https://registry.yarnpkg.com/rollup/-/rollup-2.20.0.tgz#7456fed8424a5247954958751642e9fdd0ad7485"
-  integrity sha512-hkbp//ne1om8+PQRpd81zk0KDvbJxkLZdZJh1ZNxjd1EkI0H1TmYuHqqXx88yciS+5YnMom3geubQjTeeUnNNw==
+rollup@^2.21.0:
+  version "2.21.0"
+  resolved "https://registry.yarnpkg.com/rollup/-/rollup-2.21.0.tgz#d2e114533812043d5c9b7b0a83f1b2a242e4e1d6"
+  integrity sha512-BEGgy+wSzux7Ycq58pRiWEOBZaXRXTuvzl1gsm7gqmsAHxkWf9nyA5V2LN9fGSHhhDQd0/C13iRzSh4bbIpWZQ==
   optionalDependencies:
     fsevents "~2.1.2"