       #=> "/path/to/project/_build/shared/lib/app"
 
   """
+  @spec app_path(Keyword.t) :: Path.t
   def app_path(config \\ config()) do
     config[:app_path] || cond do
       app = config[:app] ->

      #=> "/path/to/project/deps"

  """
  def deps_path(config \\ config()) do
    Path.expand config[:deps_path]
  end

      #=> "/path/to/project/_build/shared/lib/app"

  """
  @spec manifest_path(Keyword.t) :: Path.t
  def manifest_path(config \\ config()) do
    config[:app_path] ||
      if app = config[:app] do
