Adding CI on Github Actions. (#3938)

.github/workflows/ci.yml

@@ -0,0 +1,24 @@
+name: ci
+
+on:
+  push:
+    branches: [master]
+  pull_request:
+    branches: [master]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x, 14.x, 16.x]
+
+    steps:
+      - uses: actions/checkout@v2
+      - name: Setup node
+        uses: actions/setup-node@v2
+        with:
+          node-version: ${{ matrix.node }}
+      - run: npm install
+      - run: npm test

karma.conf.js

@@ -127,6 +127,9 @@ module.exports = function(config) {
       'Running on Travis.'
     );
     browsers = ['Firefox'];
+  } else if (process.env.GITHUB_ACTIONS !== 'false') {
+    console.log('Running ci on Github Actions.');
+    browsers = ['FirefoxHeadless', 'ChromeHeadless'];
   } else {
     console.log('Running locally since SAUCE_USERNAME and SAUCE_ACCESS_KEY environment variables are not set.');
     browsers = ['Firefox', 'Chrome'];