Adding in step to build release

Author: JN-Hernandez

.github/workflows/release.yml

@@ -25,7 +25,10 @@ jobs:
       - name: Install release dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install setuptools wheel twine
+          pip install setuptools wheel
+
+      - name: Build package
+        run: python setup.py sdist bdist_wheel
 
       - name: Upload release to TestPyPI
         uses: pypa/gh-action-pypi-publish@release/v1