Install pandoc in GitHub Actions

Author: jonathansick

.github/workflows/ci.yaml

@@ -55,6 +55,9 @@ jobs:
         with:
           python-version: ${{ matrix.python-version }}
 
+      - name: Install pandoc
+        run: brew install pandoc
+
       - name: Python install
         run: |
           python -m pip install --upgrade pip

tox.ini

@@ -11,6 +11,7 @@ skip_missing_interpreters = True
 description = Run unit tests
 extras =
     dev
+allowlist_externals =
     pandoc
 commands=
     pytest {posargs}