Merge pull request #27 from eric-wieser/fix-submodule-PyPI

Ensure submodules are included in the build

Author: eric-wieser

.github/workflows/pythonpublish.yml

@@ -7,6 +7,8 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v1
+      with:
+        submodules: true
     - name: Set up Python
       uses: actions/setup-python@v1
       with: