Notebook Tests (#99)

Added Action to build the notebooks at PR time

.github/workflows/build_test_notebooks.yml

@@ -0,0 +1,57 @@
+name: Build & Test Notebooks
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+  workflow_dispatch:
+
+jobs:
+  build-notebooks:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout stingray repo
+        uses: actions/checkout@v4
+        with:
+          repository: StingraySoftware/stingray
+          path: ./stingray
+          submodules: recursive
+
+      - name: Get latest commit of the PR and Checkout PR version of notebooks
+        run: |
+          PR_SHA=$(curl -s 'https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}' | jq -r .head.sha)
+          if [ "$PR_SHA" == "null" ]; then
+            echo "::error::Failed to get PR SHA"
+            exit 1
+          fi
+          echo "commit=$PR_SHA" >> $GITHUB_ENV
+          cd ./stingray/docs/notebooks # Change to the submodule directory
+          pwd
+          git fetch origin $PR_SHA:pr_temp
+          git checkout pr_temp
+      - name: Verify submodule update
+        run: |
+          cd ./stingray/docs/notebooks
+          git log -1
+      - name: Setup Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.10'
+
+      - name: Install pandoc and additional dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y pandoc fonts-freefont-ttf
+          pip install sphinx sphinx-astropy tox
+          
+      - name: Install Stingray
+        run: |
+          pip install -e ./stingray
+      - name: Run Build Docs
+        run: |
+          cd ./stingray
+          tox -e build_docs