Update python-package.yml

.github/workflows/python-package.yml

@@ -29,6 +29,7 @@ jobs:
         python -m pip install --upgrade pip
         python -m pip install black pytest
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        python -m pip install .
     - name: Format with black
       run: |
         black -l 100 ionizer/*.py tests/*.py