Fix actions

Former-commit-id: 016536a695baf8ea78b83da6b4b2bfe121e070e9

.github/workflows/main.yml

@@ -12,6 +12,9 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v2
 
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+        
       - name: Log in to Docker Hub
         uses: docker/login-action@v1
         with:
@@ -22,7 +25,7 @@ jobs:
         uses: docker/login-action@f054a8b539a109f9f41c372932f1ae047eff08c9
         with:
           registry: ghcr.io
-          username: ${{ github.actor }}
+          username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Extract metadata (tags, labels) for Docker
@@ -33,10 +36,10 @@ jobs:
 
       - name: Build and push Docker image
         id: docker_build
-        uses: docker/build-push-action@v1
+        uses: docker/build-push-action@v2
         with:
           context: .
           push: true
           tags: |
             milesial/unet:latest 
-            ghcr.io/milesial/unet:latest
+            ghcr.io/milesial/pytorch-unet:latest