Try explicitly installing type stubs

Author: ragibson

.github/workflows/python-package.yml

@@ -41,7 +41,7 @@ jobs:
       - name: Type checking with mypy
         run: |
           source env/bin/activate
-          python -m pip install mypy types-setuptools
+          python -m pip install mypy types-setuptools types-numpy types-Pillow types-click
           python -m mypy --install-types --non-interactive
       - name: Test with pytest
         run: |