Update github checkout action (#166)

.github/workflows/kitchen-sink.yml

@@ -13,10 +13,8 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      # appears that checkout@v2 uses javascript which is not compatible 
-      # with the included node version in the container image.
       - name: Checkout Code
-        uses: actions/checkout@v1
+        uses: actions/checkout@v2
 
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v1