fix GH CI (#1052)

.github/workflows/ci-testing.yml

@@ -17,7 +17,7 @@ jobs:
     # https://stackoverflow.com/a/59076067/4521646
     timeout-minutes: 20
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v1
       with:

.github/workflows/docs-check.yml

@@ -8,7 +8,7 @@ jobs:
   docs:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - uses: ammaraskar/sphinx-action@master
       with:
         # git is requried to clone the docs theme