Bump @open-wc/karma-esm from 2.16.17 to 3.0.3 (#270)

Bumps [@open-wc/karma-esm](https://github.com/open-wc/open-wc/tree/HEAD/packages/karma-esm) from 2.16.17 to 3.0.3.
- [Release notes](https://github.com/open-wc/open-wc/releases)
- [Changelog](https://github.com/open-wc/open-wc/blob/master/packages/karma-esm/CHANGELOG.md)
- [Commits](https://github.com/open-wc/open-wc/commits/@open-wc/karma-esm@3.0.3/packages/karma-esm)

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

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -42,7 +42,7 @@
   "devDependencies": {
     "@babel/preset-env": "^7.7.1",
     "@babel/preset-typescript": "^7.7.2",
-    "@open-wc/karma-esm": "^2.13.22",
+    "@open-wc/karma-esm": "^3.0.3",
     "@open-wc/testing": "^2.5.19",
     "@rollup/plugin-node-resolve": "^8.0.0",
     "@types/mocha": "^7.0.2",