Use github actions v4

Author: tboggs

.github/workflows/python-package.yml

@@ -16,12 +16,12 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [2.7, 3.6, 3.7, 3.8, 3.9, "3.10"]
+        python-version: [2.7, 3.6.15, 3.7, 3.8, 3.9, "3.10"]
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
     - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v2
+      uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install dependencies