camino 1.0.8

Added

• New methods canonicalize_utf8, read_link_utf8 and read_dir_utf8 return Utf8PathBufs, erroring out if a resulting path is not valid UTF-8.
• New feature proptest1 introduces proptest Arbitrary impls for Utf8PathBuf and
  Box<Utf8Path> (#18, thanks mcronce for your first contribution!)