add doctest to list_policies/2
TODO: Add description
If available in Hex, the package can be installed by adding acx to your list of dependencies in mix.exs:
def deps do [ {:acx, "~> 0.1.0"} ] end
Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/acx.