Issue #74: Set env vars for linux

.github/workflows/ci.yml

@@ -6,9 +6,6 @@ jobs:
       matrix:
         os: [ubuntu-18.04, macos-latest, windows-latest]
 
-    services:
-      - xfb
-
     runs-on: ${{ matrix.os }}
 
     steps:
@@ -22,6 +19,12 @@ jobs:
           python -m pip install --upgrade pip
           pip install tox
 
+      - name: Set environmental variables for linux
+        if: shell == "bash"
+        env:
+          LD_LIBRARY_PATH: ${CI_PROJECT_DIR}/.tox/py36/lib/python3.6/site-packages/PySide2/Qt/plugins/platforms
+          DISPLAY: localhost:1
+
       - name: Run tox
         run: |
           tox