create a 'master' docker tag for the latest master version

.github/workflows/build.yml

@@ -40,18 +40,28 @@ jobs:
 
       # Docker
       - name: Login to Container Registry
-        if: ${{ github.ref_type == 'tag' && matrix.java == '8' }}
+        if: ${{ matrix.java == '8' }}
         uses: docker/login-action@v2
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
-      - name: Docker build and push
+      - name: Docker build and push tag
         uses: docker/build-push-action@v4
+        if: ${{ matrix.java == '8' && github.ref_type == 'tag' }}
         with:
           context: .
+          push: true
           platforms: linux/amd64,linux/arm/v7
-          push: ${{ github.ref_type == 'tag' && matrix.java == '8' }}
           tags: |
             athou/commafeed:latest
             athou/commafeed:${{ github.ref_name }}
+
+      - name: Docker build and push master
+        uses: docker/build-push-action@v4
+        if: ${{ matrix.java == '8' && github.ref_name == 'master' }}
+        with:
+          context: .
+          push: true
+          platforms: linux/amd64,linux/arm/v7
+          tags: athou/commafeed:master