Switch to using strings for session IDs.

Go/Types.elm

@@ -10,7 +10,7 @@ type alias Update = (Color, List Cell)
 type alias Model = 
     { sessionColor : Color
     , sessionUrl : String
-    , sessionId : Int
+    , sessionId : String
     , sessionSize : Int
 
     , error : Maybe String
@@ -21,7 +21,7 @@ type alias Model =
 type alias Flags =
     { black : Bool
     , url : String
-    , id : Int
+    , id : String
     , size : Int
     }
 

Go/Ws.elm

@@ -3,7 +3,7 @@ import Go.Types exposing (..)
 import WebSocket
 
 wsUrl : Model -> String
-wsUrl m = (m.sessionUrl ++ "/game/" ++ (toString m.sessionId))
+wsUrl m = (m.sessionUrl ++ "/game/" ++ toString m.sessionId)
 
 encodeCell : Cell -> String
 encodeCell ((x, y), c) = "place "