Add support for draft socket types

src/ZMQ.jl

@@ -28,6 +28,7 @@ include("socket.jl")
 include("sockopts.jl")
 include("message.jl")
 include("comm.jl")
+include("draft.jl")
 
 function __init__()
     major = Ref{Cint}()

src/draft.jl

@@ -0,0 +1,18 @@
+# Draft ZMQ capabilities
+# Note that usage of these APIs is not guaranteed to be compatible across ZMQ versions.
+# Use at your own risk.
+module Draft
+
+export SERVER, CLIENT, RADIO, DISH, GATHER, SCATTER, DGRAM
+
+# Draft Socket Types, as of ZMQ 4.3.2
+const SERVER = 12
+const CLIENT = 13
+const RADIO = 14
+const DISH = 15
+const GATHER = 16
+const SCATTER = 17
+const DGRAM = 18
+
+end # module Draft
+