Update python.yml

Author: wenbinf

.github/workflows/python.yml

@@ -17,10 +17,10 @@ jobs:
 
     steps:
     - uses: actions/checkout@v2
-    - name: Use Python ${{ matrix.node-version }}
+    - name: Use Python ${{ matrix.python-version }}
       uses: actions/setup-python@v2
       with:
-        node-version: ${{ matrix.node-version }}
-        cache: 'yarn'
+        python-version: ${{ matrix.python-version }}
+        cache: 'pip'
     - run: make
     - run: make test-travis