test: Switch local Chrome, Edge, Firefox, and Safari launchers to Web…

…Driver-based (shaka-project#3921)

* test: Switch local Chrome, Edge, Firefox, and Safari launchers to WebDriver-based

This will enable WebDriver-based screenshot tests in local test runs.

* test: Add screenshots for Edge on Mac

package.json

@@ -11,8 +11,6 @@
     }
   ],
   "devDependencies": {
-    "@chiragrupani/karma-chromium-edge-launcher": "^2.1.0",
-    "@onslip/karma-safari-launcher": "^1.0.1",
     "@teppeis/clutz": "^1.0.29-4c95e12.v20190929",
     "awesomplete": "^1.1.4",
     "babel-core": "^6.26.3",
@@ -37,13 +35,11 @@
     "jsdoc": "github:joeyparrish/jsdoc#45c271fa",
     "karma": "^6.2.0",
     "karma-babel-preprocessor": "^7.0.0",
-    "karma-chrome-launcher": "^2.2.0",
     "karma-coverage": "^1.1.2",
-    "karma-edge-launcher": "^0.4.2",
-    "karma-firefox-launcher": "^1.1.0",
     "karma-ie-launcher": "^1.0.0",
     "karma-jasmine": "^3.3.1",
     "karma-jasmine-ajax": "^0.1.13",
+    "karma-local-wd-launcher": "^1.3.1",
     "karma-opera-launcher": "^1.0.0",
     "karma-sourcemap-loader": "^0.3.7",
     "karma-spec-reporter": "0.0.32",