Bump karma-firefox-launcher from 1.3.0 to 2.0.0

Bumps [karma-firefox-launcher](https://github.com/karma-runner/karma-firefox-launcher) from 1.3.0 to 2.0.0.
- [Release notes](https://github.com/karma-runner/karma-firefox-launcher/releases)
- [Changelog](https://github.com/karma-runner/karma-firefox-launcher/blob/master/CHANGELOG.md)
- [Commits](karma-runner/karma-firefox-launcher@v1.3.0...v2.0.0)

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

package.json

@@ -24,7 +24,7 @@
     "karma-chrome-launcher": "^3.1.0",
     "karma-coverage": "2.0.3",
     "karma-es6-shim": "1.0.0",
-    "karma-firefox-launcher": "1.3.0",
+    "karma-firefox-launcher": "2.0.0",
     "karma-jasmine": "^3.3.1",
     "karma-mocha-reporter": "2.2.5",
     "karma-phantomjs-launcher": "1.0.4",