build: run edge tests on browserstack

Moves the Edge tests to Browserstack to avoid the recent issues with Saucelabs.
Also moves the desktop Safari tests to Saucelabs to reduce flakes.

Author: crisbeto

test/browser-providers.js

@@ -7,9 +7,9 @@
  *   - `saucelabs`: Launches the browser within Saucelabs
  */
 const browserConfig = {
-  'Edge83':            {unitTest: {target: 'saucelabs'}},
+  'Edge83':            {unitTest: {target: 'browserstack'}},
   'iOS13':             {unitTest: {target: 'saucelabs'}},
-  'Safari13':          {unitTest: {target: 'browserstack'}},
+  'Safari13':          {unitTest: {target: 'saucelabs'}},
 };
 
 /** Exports all available custom Karma browsers. */

test/karma-browsers.json

@@ -19,17 +19,18 @@
     "platformName": "iOS",
     "deviceName": "iPhone XS Simulator"
   },
-  "SAUCELABS_EDGE83": {
-    "base": "SauceLabs",
-    "browserName": "MicrosoftEdge",
-    "browserVersion": "83.0",
-    "platformName": "Windows 10"
-  },
-  "BROWSERSTACK_SAFARI13": {
+  "BROWSERSTACK_EDGE83": {
     "base": "BrowserStack",
-    "browser": "Safari",
-    "browser_version": "13.1",
-    "os": "OS X",
-    "os_version": "Catalina"
+    "browser": "Edge",
+    "browser_version": "83.0",
+    "os": "Windows",
+    "os_version": "10"
+  },
+  "SAUCELABS_SAFARI13": {
+    "base": "SauceLabs",
+    "browserName": "safari",
+    "browserVersion": "13.1",
+    "platformName": "macOS 10.15",
+    "deviceName": "macOS Safari"
   }
 }