Merge pull request #2819 from sbadugu/satish_docker_official_image_update

Update to the latest gateway version 5.6.0

library/kaazing-gateway

@@ -1,4 +1,4 @@
 # maintainer: Kaazing Docker Maintainers <https://github.com/kaazing/gateway.docker/issues> (@kaazing)
 
-latest: git://github.com/kaazing/gateway.docker@27281b1f0a8d09ce3897ba3325f1da669266d0b1
-5.5.0: git://github.com/kaazing/gateway.docker@27281b1f0a8d09ce3897ba3325f1da669266d0b1
+latest: git://github.com/kaazing/gateway.docker@a40c8da9d2c2925bdd78b9a6d1b6da3fe89322d1 
+5.6.0: git://github.com/kaazing/gateway.docker@a40c8da9d2c2925bdd78b9a6d1b6da3fe89322d1