Add CI test

.github/workflows/ci.yaml

@@ -0,0 +1,35 @@
+name: CI tests
+
+on:
+  push:
+    paths-ignore:
+      - 'README.md'
+  pull_request:
+    paths-ignore:
+      - 'README.md'
+
+jobs:
+  linux:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        version:
+          - '2.19.2'
+          - '3.5'
+          -
+    steps:
+    - name: Install pandoc
+      uses: pandoc/actions/setup@main
+      with:
+        version: ${{ matrix.version }}
+    - name: Verify
+      run: |
+        if [ -z "${{ matrix.version }}" ]; then
+            # just check that pandoc is available
+            pandoc -v
+        else
+            # check that we got the right version
+            [ "pandoc ${{ matrix.version }}" = "$(pandoc -v | head -n1)" ]
+        fi
+