Install qt and xvfb

.gitlab-ci.yml

@@ -29,6 +29,7 @@ cache:
 
 before_script:
   - apt-get update --yes
+  - apt-get install --yes python3-pyqt5 xvfb xdg-utils
   - python -m pip install --upgrade pip
   - python --version  # For debugging
   - pip install virtualenv