gradient boosted trees: Install dependencies

Author: VesnaT

.github/workflows/macos_workflow.yml

@@ -26,6 +26,8 @@ jobs:
         with:
           python-version: ${{ matrix.python }}
 
+      - name: Install system dependencies on MacOS
+        run: brew install libomp
       - name: Install Tox
         run: pip install tox
 

tox.ini

@@ -26,6 +26,7 @@ setenv =
 deps =
     pyqt5==5.12.*
     pyqtwebengine==5.12.*
+    -r {toxinidir}/requirements-opt.txt
 commands_pre =
     # Verify installed packages have compatible dependencies
     pip check