Use actions/checkout@v2

Author: RadoRado

.github/workflows/django.yml

@@ -15,7 +15,7 @@ jobs:
         # needed because the postgres container does not provide a healthcheck
         options: --health-cmd pg_isready --health-interval 10s --health-timeout 5s --health-retries 5
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Set up Python 3.7
       uses: actions/setup-python@v1
       with: