Build docker image for tagged release.

Author: adieu

circle.yml

@@ -41,3 +41,9 @@ deployment:
     commands:
       - docker login -e $DOCKER_EMAIL -u $DOCKER_LOGIN -p $DOCKER_PASSWORD
       - docker push $DOCKER_IMAGE_NAME
+  hub_tag:
+    tag: /^v[0-9]+(\.[0-9]+){2}(-.+|[^-.]*)$/
+    owner: kubeup
+    commands:
+      - docker login -e $DOCKER_EMAIL -u $DOCKER_LOGIN -p $DOCKER_PASSWORD
+      - docker push $DOCKER_IMAGE_NAME