fix: fix compile-time warnings (#43)

Author: tiagopog

lib/params.ex

@@ -124,8 +124,10 @@ defmodule Params do
 
   @doc false
   def optional(module) when is_atom(module) do
-    module.__info__(:attributes) |> Keyword.get(:optional) |> case do
-      nil -> module.__changeset__ |> Map.keys
+    module.__info__(:attributes)
+    |> Keyword.get(:optional)
+    |> case do
+      nil -> module.__changeset__() |> Map.keys()
       x -> x
     end
   end

mix.exs

@@ -15,7 +15,8 @@ defmodule Params.Mixfile do
       package: package(),
       build_embedded: Mix.env() == :prod,
       start_permanent: Mix.env() == :prod,
-      dialyzer: [plt_add_apps: [:ecto]]
+      dialyzer: [plt_add_apps: [:ecto]],
+      xref: [exclude: [Ecto.Changeset]]
     ]
   end