Bump checkout version

Author: hross

.github/workflows/test.yml

@@ -11,15 +11,15 @@ jobs:
   units:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - run: npm ci
     - run: npm test
 
   # test action works running from the graph  
   test:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
+    - uses: actions/checkout@v2
     - uses: ./
       with:
         milliseconds: 1000