Following error displayed when running mix docker.build. I am not sure if this is related to #15 where app and version needs to specified, the referenced distillery's issue, bitwalker/distillery#201

** (FunctionClauseError) no function clause matching in IO.chardata_to_string/1
(elixir) lib/io.ex:445: IO.chardata_to_string(nil)
(elixir) lib/path.ex:475: Path.do_join/3
(elixir) lib/path.ex:470: Path.join/2
(elixir) lib/path.ex:450: Path.join/1
(distillery) lib/mix/lib/releases/archiver.ex:31: Mix.Releases.Archiver.make_tar/1
(distillery) lib/mix/lib/releases/archiver.ex:17: Mix.Releases.Archiver.archive/1
(distillery) lib/distillery/tasks/release.ex:113: Mix.Tasks.Release.run/1
(mix) lib/mix/task.ex:294: Mix.Task.run_task/3

The command '/bin/sh -c mix release --env=prod --verbose' returned a non-zero code: 1
** (MatchError) no match of right hand side value: {%IO.Stream{device: :standard_io, line_or_bytes: :line, raw: false}, 1}
lib/mix_docker.ex:153: MixDocker.system!/2
lib/mix_docker.ex:123: MixDocker.with_dockerfile/2
lib/mix_docker.ex:18: MixDocker.build/1
(mix) lib/mix/task.ex:294: Mix.Task.run_task/3
(mix) lib/mix/cli.ex:58: Mix.CLI.run_task/2