0.8.0
-----

* Added conversion from and into larger integer types, including
  conversions between `Z64` and `Z32`.
* Added fallible conversion into smaller integer types.
* Added fallible conversion from `&str`.

0.7.2
-----

* Fixed an overflow in conversions from unsigned integers.

0.7.0
-----

* `Z32` and `Z64` now implement
  [FromStr](https://doc.rust-lang.org/std/str/trait.FromStr.html)

0.6.0
-----

* `Z32` and `Z64` are now `#[repr(transparent)]`