whenxuan: update the unittest

Author: wwhenxuan

.github/workflows/unittest.yml

@@ -27,7 +27,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install flake8 pytest
-        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+        pip install torch
     - name: Test with unittest
       run: |
         python -m unittest discover -v