Temporarily use sphinx fork to verify fixes

.circleci/config.yml

@@ -97,6 +97,7 @@ commands:
       - run:
           name: Install Python dependencies
           command: |
+            python -m pip install --user git+https://github.com/ayshih/sphinx@svg_fix
             python -m pip install --user \
                 numpy<< parameters.numpy_version >> \
                 -r requirements/doc/doc-requirements.txt