install correct requirements file in workflow

.github/workflows/unit_tests.yml

@@ -28,7 +28,7 @@ jobs:
         run: |
           python -m pip install --upgrade pip
           pip install pytest
-          if [ -f requirements_dev.txt ]; then pip install -r requirements_dev.txt; fi
+          if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
 
       - name: Test with pytest
         run: |