build: update karma dependencies

Bumps the various Karma-related dependencies in an effort to resolve the Saucelabs issues.

Author: crisbeto

package.json

@@ -130,15 +130,15 @@
     "inquirer": "^7.1.0",
     "jasmine-core": "^3.5.0",
     "kagekiri": "^1.0.18",
-    "karma": "^4.4.1",
-    "karma-browserstack-launcher": "^1.3.0",
-    "karma-chrome-launcher": "^2.2.0",
-    "karma-firefox-launcher": "^1.0.1",
+    "karma": "^5.2.3",
+    "karma-browserstack-launcher": "^1.6.0",
+    "karma-chrome-launcher": "^3.1.0",
+    "karma-firefox-launcher": "^1.3.0",
     "karma-jasmine": "^3.1.1",
-    "karma-parallel": "^0.3.0",
+    "karma-parallel": "^0.3.1",
     "karma-requirejs": "^1.1.0",
-    "karma-sauce-launcher": "^2.0.2",
-    "karma-sourcemap-loader": "^0.3.7",
+    "karma-sauce-launcher": "~4.0.0",
+    "karma-sourcemap-loader": "^0.3.8",
     "madge": "^3.4.4",
     "marked": "^1.0.0",
     "merge2": "^1.2.3",