Try to get FunctionalJavascript working.

.github/workflows/build-2.x.yml

@@ -118,6 +118,15 @@ jobs:
       - name: Test scripts
         run: $SCRIPT_DIR/travis_scripts.sh
 
+        # needed for FunctionalJavascript
+      - name: Set up chromedriver
+        uses: actions/checkout@v2
+        uses: nanasess/setup-chromedriver@v1
+        run: |
+          export DISPLAY=:99
+          chromedriver --url-base=/wd/hub &
+          sudo Xvfb -ac :99 -screen 0 1280x1024x24 > /dev/null 2>&1 & # optional
+
       - name: PHPUNIT tests
         run: |
           cd $DRUPAL_DIR/web/core