incorporate matrix approach for github actions

.github/workflows/docker-image.yml

@@ -12,7 +12,19 @@ jobs:
 
     runs-on: ubuntu-latest
 
+    strategy:
+      matrix:
+        dockerfile: [Dockerfile.pipe, Dockerfile.api, Dockerfile.dash]
+
     steps:
     - uses: actions/checkout@v3
-    - name: Build the Docker image
-      run: docker build . --file Dockerfile --tag my-image-name:$(date +%s)
+    - name: Set up Docker Buildx
+      uses: docker/setup-buildx-action@v1
+    - name: Build and push
+      uses: docker/build-push-action@v2
+      with:
+        context: .
+        file: ${{ matrix.dockerfile }}
+        push: true
+        tags: my-image-name:$(date +%s)
+