Merge branch '6.0.x'

Author: bclozel

ci/tasks/promote-version.yml

@@ -4,7 +4,7 @@ image_resource:
   type: registry-image
   source:
     repository: springio/concourse-release-scripts
-    tag: '0.3.4'
+    tag: '0.4.0-SNAPSHOT'
     username: ((docker-hub-username))
     password: ((docker-hub-password))
 inputs: