ui: Initial Elm UI import

Merged from https://github.com/jhillyerd/inbucket-elm

Uses https://github.com/halfzebra/create-elm-app

ui/src/Data/Message.elm

@@ -0,0 +1,44 @@
+module Data.Message exposing (..)
+
+import Json.Decode as Decode exposing (..)
+import Json.Decode.Pipeline exposing (..)
+
+
+type alias Message =
+    { mailbox : String
+    , id : String
+    , from : String
+    , to : List String
+    , subject : String
+    , date : String
+    , size : Int
+    , seen : Bool
+    , body : Body
+    }
+
+
+type alias Body =
+    { text : String
+    , html : String
+    }
+
+
+decoder : Decoder Message
+decoder =
+    decode Message
+        |> required "mailbox" string
+        |> required "id" string
+        |> optional "from" string ""
+        |> required "to" (list string)
+        |> optional "subject" string ""
+        |> required "date" string
+        |> required "size" int
+        |> required "seen" bool
+        |> required "body" bodyDecoder
+
+
+bodyDecoder : Decoder Body
+bodyDecoder =
+    decode Body
+        |> required "text" string
+        |> required "html" string