TODOs

# TODOs

## Map

- Add --options flag to rbdmap that allows passing comma separated options to be passed. This needs a unmarshaller to parse the values into krbd.Options{}.
- Replicate iotest.WriteLogger(w io.Writer) that accepts a WriteCloser and prints strings instead of hex for verbose logging.
- Convert use of io.Writer to io.WriteCloser and w.Close() before exiting.
- Add option to read keyring and secrets files for credentials.

## Unmap

- Add option to specify device path / name