Add missing Docker login step (#106)

Signed-off-by: Reinhard Nägele <[email protected]>

Author: unguiculus

.github/workflows/release.yaml

@@ -47,6 +47,13 @@ jobs:
           git tag --annotate --message "Tag for release $tag" "$tag"
           git push origin "refs/tags/$tag"
 
+      - name: Login to registry
+        uses: docker/login-action@v1
+        with:
+          registry: quay.io
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
       - name: Release
         run: mage -v release
         env: