Update dependency karma to v5 (#30)

Author: renovate-bot

package.json

@@ -32,7 +32,7 @@
     "acorn-walk": "7.1.1",
     "chai": "4.2.0",
     "http-server": "0.12.3",
-    "karma": "4.4.1",
+    "karma": "5.0.9",
     "karma-chai": "0.1.0",
     "karma-chrome-launcher": "3.1.0",
     "karma-firefox-launcher": "1.3.0",