fix compile warnings

config/config.exs

@@ -1,6 +1,6 @@
 # This file is responsible for configuring your application
 # and its dependencies with the aid of the Mix.Config module.
-use Mix.Config
+import Config
 
 # This configuration is loaded before any dependency and is restricted
 # to this project. If another project depends on this project, this

lib/chartkick.ex

@@ -1,11 +1,5 @@
 defmodule Chartkick do
   require EEx
-  Module.put_attribute(
-    __MODULE__,
-    :poison,
-    if(Code.ensure_loaded?(Poison), do: Poison, else: nil)
-  )
-  @json_serializer Application.get_env(:chartkick, :json_serializer) || @poison
 
   gen_chart_fn = fn (chart_type) ->
     def unquote(
@@ -89,7 +83,7 @@ defmodule Chartkick do
     opts
     |> Keyword.take(@options)
     |> Enum.into(%{})
-    |> @json_serializer.encode!()
+    |> Poison.encode!()
   end
 
   defp options_json(opts) when is_bitstring(opts) do

mix.exs

@@ -17,7 +17,7 @@ defmodule Chartkick.Mixfile do
   #
   # Type `mix help compile.app` for more information
   def application do
-    [applications: [:logger]]
+    [extra_applications: [:logger, :eex]]
   end
 
   defp description do
@@ -47,6 +47,6 @@ defmodule Chartkick.Mixfile do
   # Type `mix help deps` for more examples and options
   defp deps do
     [{ :elixir_uuid, "~> 1.2" },
-     {:poison, "~> 3.0"}]
+     {:poison, "~> 5.0"}]
   end
 end

mix.lock

@@ -1,5 +1,5 @@
 %{
-  "elixir_uuid": {:hex, :elixir_uuid, "1.2.1", "dce506597acb7e6b0daeaff52ff6a9043f5919a4c3315abb4143f0b00378c097", [:mix], [], "hexpm"},
-  "poison": {:hex, :poison, "3.1.0", "d9eb636610e096f86f25d9a46f35a9facac35609a7591b3be3326e99a0484665", [:mix], [], "hexpm"},
+  "elixir_uuid": {:hex, :elixir_uuid, "1.2.1", "dce506597acb7e6b0daeaff52ff6a9043f5919a4c3315abb4143f0b00378c097", [:mix], [], "hexpm", "f7eba2ea6c3555cea09706492716b0d87397b88946e6380898c2889d68585752"},
+  "poison": {:hex, :poison, "5.0.0", "d2b54589ab4157bbb82ec2050757779bfed724463a544b6e20d79855a9e43b24", [:mix], [{:decimal, "~> 2.0", [hex: :decimal, repo: "hexpm", optional: true]}], "hexpm", "11dc6117c501b80c62a7594f941d043982a1bd05a1184280c0d9166eb4d8d3fc"},
   "uuid": {:hex, :uuid, "1.1.8", "e22fc04499de0de3ed1116b770c7737779f226ceefa0badb3592e64d5cfb4eb9", [:mix], [], "hexpm"},
 }