[test] add test for file_handler, ignore ui test in gh action

.github/workflows/python-app.yml

@@ -20,14 +20,6 @@ jobs:
       uses: actions/setup-python@v2
       with:
         python-version: 3.6
-    - name: setup
-      env:
-        DISPLAY: ':99.0'
-      run: |
-        sudo apt install libxkbcommon-x11-0 libxcb-icccm4 libxcb-image0 libxcb-keysyms1 libxcb-randr0 libxcb-render-util0
-        sudo apt install libxcb-xinerama0 libxcb-xfixes0
-        /sbin/start-stop-daemon --start --quiet --pidfile /tmp/custom_xvfb_99.pid --make-pidfile --background --exec /usr/bin/Xvfb -- :99 -screen 0 1920x1200x24 -ac +extension GLX
-
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
@@ -41,4 +33,4 @@ jobs:
         flake8 . --count --exit-zero --max-complexity=10 --max-line-length=127 --statistics
     - name: Test with pytest
       run: |
-        pytest
+        pytest --ignore nixview/test/test_ui.py