   end
 
   defp parse_version("git version " <> version) do
-    String.split(version, ".")
+    version
+    |> String.split(".")
     |> Enum.take(3)
     |> Enum.map(&to_integer/1)
-    |> List.to_tuple
+    |> List.to_tuple()
   end
 
   defp to_integer(string) do

    path = opts[:checkout]
    File.rm_rf!(path)
    File.mkdir_p!(path)
    File.cd!(path, fn ->
      git!(["init", "--quiet"])
      git!(["--git-dir=.git", "remote", "add", "origin", opts[:git]])

  ## Helpers

  defp validate_git_options(opts) do
    err =
      "You should specify only one of branch, ref or tag, and only once. " <>
        "Error on Git dependency: #{opts[:git]}"

    validate_single_uniq(opts, [:branch, :ref, :tag], err)
  end

  defp validate_single_uniq(opts, take, error) do
    case Keyword.take(opts, take) do
      [] -> opts
      [_] -> opts
      _ -> Mix.raise(error)
    end
  end

