ci: Update to checkout action v2

Signed-off-by: John Andersen <[email protected]>

Author: pdxjohnny

.github/workflows/testing.yml

@@ -14,7 +14,7 @@ jobs:
         node-version: [12.x]
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v1
       with:
@@ -41,7 +41,7 @@ jobs:
         python-version: [3.7]
 
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - name: Set up Python ${{ matrix.python-version }}
       uses: actions/setup-python@v1
       with: