Bump actions/setup-python from 1 to 2.3.1 (#129)

Author: dependabot[bot]

.github/workflows/python.yml

@@ -19,7 +19,7 @@ jobs:
     steps:
       - uses: actions/[email protected]
       - name: Set up Python ${{ matrix.python-version }}
-        uses: actions/setup-python@v1
+        uses: actions/setup-python@v2.3.1
         with:
           python-version: ${{ matrix.python-version }}
       - name: Install dependencies