update action

Author: reliveyy

.github/workflows/ci.yml

@@ -17,5 +17,7 @@ jobs:
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
+      - name: Checkout
+        uses: actions/checkout@v2
       - name: Build and push
         run: tools/build utils and tools/push utils