update swarm to 0.4.0-rc1

Signed-off-by: Andrea Luzzardi <[email protected]>

library/swarm

@@ -2,5 +2,6 @@
 # maintainer: Victor Vieux <[email protected]> (@vieux)
 # maintainer: Alexandre Beslic <[email protected]> (@abronan)
 
+0.4.0-rc1: git://github.com/docker/swarm-library-image@ef91e04360892919954c178f9c0f70f43a9f900b
 0.3.0: git://github.com/docker/swarm-library-image@206d90c3d59ccc2e1b232d37edf3b492ca81693b
 latest: git://github.com/docker/swarm-library-image@206d90c3d59ccc2e1b232d37edf3b492ca81693b