BuildArgs converts build options into the cli arguments used to call `docker build`.

LoginArgs converts login options into the cli arguments used to call `docker login`.

NewRunner returns a new Runner with the stdout and stderr defaulting to os.

PushArgs converts tags into the cli arguments used to call `docker push`.

RunBuild runs a docker build and tags the resulting image.

RunLogin runs a docker login.

RunPush runs a docker push for each tag.

Runner executes standard commands.