Install package for CI

Author: jseabold

.github/workflows/python-package.yml

@@ -36,4 +36,5 @@ jobs:
         flake8 . --count --exit-zero --max-complexity=10 --max-line-length=89 --statistics
     - name: Test with pytest
       run: |
+        python setup.py install
         pytest -W error --cov=pandas_select --cov-report term-missing:skip-covered