Combine protocol version with rest of kernel info

ipython-kernel/src/IHaskell/IPython/Message/Writer.hs

@@ -25,7 +25,7 @@ instance ToJSON LanguageInfo where
 instance ToJSON Message where
   toJSON rep@KernelInfoReply{} =
     object
-      [ "protocol_version" .= string "5.0"  -- current protocol version, major and minor
+      [ "protocol_version" .= protocolVersion rep
       , "banner" .= banner rep
       , "implementation" .= implementation rep
       , "implementation_version" .= implementationVersion rep

ipython-kernel/src/IHaskell/IPython/Types.hs

@@ -287,6 +287,7 @@ data Message =
              -- | A response to a KernelInfoRequest.
                KernelInfoReply
                  { header :: MessageHeader
+                 , protocolVersion :: String -- ^ current protocol version, major and minor
                  , banner :: String -- ^ Kernel information description e.g. (IHaskell 0.8.3.0 GHC 7.10.2)
                  , implementation :: String -- ^ e.g. IHaskell
                  , implementationVersion :: String -- ^ The version of the implementation

main/Main.hs

@@ -239,6 +239,7 @@ replyTo _ KernelInfoRequest{} replyHeader state =
   return
     (state, KernelInfoReply
               { header = replyHeader
+              , protocolVersion = "5.0"
               , banner = "IHaskell " ++ VERSION_ipython_kernel ++ " GHC " ++ VERSION_ghc
               , implementation = "IHaskell"
               , implementationVersion = VERSION_ipython_kernel