Bump docker-dev to 1.6.0

library/docker-dev

@@ -1,8 +1,8 @@
 # maintainer: Tianon Gravi <[email protected]> (@tianon)
 
-1.5.0: git://github.com/docker/[email protected].0
-1.5: git://github.com/docker/[email protected].0
-1: git://github.com/docker/docker@v1.5.0
-latest: git://github.com/docker/docker@v1.5.0
+1.6.0: git://github.com/docker/[email protected].0
+1.6: git://github.com/docker/[email protected].0
+1: git://github.com/docker/docker@v1.6.0
+latest: git://github.com/docker/docker@v1.6.0
 
 # "supported": one tag per major, only upstream-supported majors (which is currently only "latest")