updates list rest api

- list no longer returns a json array
  but a json object, which contains a
  "messages" json array instead

lib/bump/messages.ex

@@ -16,12 +16,12 @@ defmodule Bump.Messages do
       Repo.delete_all(from m in "messages", where: m.id == ^res.id)
     %{data: res.data, timestamp: res.timestamp}
     else
-      nil
+    %{} 
     end
 
   end
 
-  def peak(sender) do
+  def peek(sender) do
     query = from m in "messages",
             where: m.sender == ^sender,
             order_by: [desc: m.timestamp],