ui: Get UI to compile with Elm 0.19

ui/src/Data/Date.elm

@@ -1,21 +1,11 @@
 module Data.Date exposing (date)
 
-import Date exposing (Date)
 import Json.Decode as Decode exposing (..)
+import Time exposing (Posix)
 
 
-{-| Decode an ISO 8601 date
+{-| Decode a POSIX milliseconds timestamp. Currently faked until backend API is updated.
 -}
-date : Decoder Date
+date : Decoder Posix
 date =
-    let
-        convert : String -> Decoder Date
-        convert raw =
-            case Date.fromString raw of
-                Ok date ->
-                    succeed date
-
-                Err error ->
-                    fail error
-    in
-    string |> andThen convert
+    succeed (Time.millisToPosix 0)