修改了action默认镜像

.github/workflows/python-test.yml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   build:
-    runs-on: "ubuntu-20.04"
+    runs-on: "ubuntu-latest"
 
     steps:
       - uses: actions/checkout@v2
@@ -19,7 +19,7 @@ jobs:
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
-          pip install pytest
+          pip install -r requirements.txt -i https://pypi.tuna.tsinghua.edu.cn/simple
       - name: Run tests
         run: |
           python -m unittest discover -s tests