Start xvfb on Ubuntu

Author: alygin

.github/workflows/ci.yml

@@ -13,6 +13,10 @@ jobs:
     - uses: actions/setup-node@v1
       with:
         node-version: '12.12'
+    - name: Start xvfb
+      if: matrix.os == 'ubuntu-20.04'
+      run: |
+        start-stop-daemon --start -b -x /usr/bin/Xvfb :1
     - name: Install dependencies
       run: npm install
     - name: Build
@@ -24,4 +28,4 @@ jobs:
       run: npm test --silent
     - name: Test Linux
       if: matrix.os == 'ubuntu-20.04'
-      run: xvfb-run --auto-servernum npm test --silent
+      run: npm test --silent