Upgrade karma to 6.4.2 (#1305)

Author: wmorland

client-rest/package-lock.json

@@ -37,7 +37,7 @@
     "codelyzer": "6.0.2",
     "jasmine-core": "~2.99.1",
     "jasmine-spec-reporter": "~4.2.1",
-    "karma": "~6.3.16",
+    "karma": "^6.4.2",
     "karma-chrome-launcher": "~2.2.0",
     "karma-coverage-istanbul-reporter": "~1.4.2",
     "karma-jasmine": "~1.1.1",