Also test with PySide2 on python>=3.5

.gitlab-ci.yml

@@ -58,6 +58,9 @@ debian9:
     - pip install --find-links http://www.silx.org/pub/wheelhouse/ --trusted-host www.silx.org --only-binary pyopencl pyopencl
     - pip install --pre --find-links artifacts/ --only-binary silx silx[full]
     - python -c "import silx.test, sys; sys.exit(silx.test.run_tests());"
+    - pip uninstall -y PyQt5
+    - pip install PySide2
+    - python -c "import silx.test, sys; sys.exit(silx.test.run_tests());"
 
 
 windows_test_python35: