remove karma-firefox-launcher

Author: theinterned

package-lock.json

@@ -28,7 +28,6 @@
     "karma": "^4.4.1",
     "karma-chai": "^0.1.0",
     "karma-chrome-launcher": "^3.1.0",
-    "karma-firefox-launcher": "^1.2.0",
     "karma-mocha": "^1.3.0",
     "karma-mocha-reporter": "^2.2.5",
     "mocha": "^6.2.2",