Update test dependencies

Author: abetlen

.github/workflows/test.yaml

@@ -26,7 +26,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies
         run: |
-          python -m pip install --upgrade pip pytest cmake scikit-build setuptools fastapi httpx uvicorn
+          python -m pip install --upgrade pip pytest cmake scikit-build setuptools fastapi sse-starlette httpx uvicorn
           pip install . -v
       - name: Test with pytest
         run: |