Add upload-artifact job to CI workflow

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

.github/workflows/ci.yml

@@ -219,6 +219,38 @@ jobs:
         if: always()
         uses: crazy-max/ghaction-dump-context@v1
 
+  upload-artifact:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v2.3.3
+      -
+        name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      -
+        name: Build and export
+        uses: ./
+        with:
+          context: ./test
+          file: ./test/Dockerfile-multi
+          platforms: linux/amd64,linux/arm64
+          tags: name/app:latest
+          outputs: type=oci,dest=/tmp/image.tar
+      -
+        name: Upload artifact
+        uses: actions/upload-artifact@v2
+        with:
+          name: app
+          path: /tmp/image.tar
+      -
+        name: Dump context
+        if: always()
+        uses: crazy-max/ghaction-dump-context@v1
+
   registry-cache:
     runs-on: ubuntu-latest
     services: