Bump @rollup/plugin-commonjs from 12.0.0 to 13.0.0

Bumps [@rollup/plugin-commonjs](https://github.com/rollup/plugins) from 12.0.0 to 13.0.0.
- [Release notes](https://github.com/rollup/plugins/releases)
- [Commits](rollup/plugins@commonjs-v12.0.0...commonjs-v13.0.0)

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

package.json

@@ -49,7 +49,7 @@
     "@babel/preset-env": "^7.6.3",
     "@babel/preset-typescript": "^7.6.0",
     "@open-wc/karma-esm": "^2.9.0",
-    "@rollup/plugin-commonjs": "^12.0.0",
+    "@rollup/plugin-commonjs": "^13.0.0",
     "@rollup/plugin-node-resolve": "^8.0.0",
     "@types/chai": "^4.2.4",
     "@types/mocha": "^7.0.2",