png 0.15.3

PNG decoding and encoding library in pure Rust
Documentation
## 0.15.3

* Fix panic while trying to encode empty images. Such images are no longer
  accepted and error when calling `write_header` before any data has been
  written. The specification does not permit empty images.

## 0.15.2

* Fix `EXPAND` transformation to leave bit depths above 8 unchanged

## 0.15.1

* Fix encoding writing invalid chunks. Images written can be corrected: see
  https://github.com/image-rs/image/issues/1074 for a recovery.
* Fix a panic in bit unpacking with checked arithmetic (e.g. in debug builds)
* Added better fuzzer integration
* Update `term`, `rand` dev-dependency
* Note: The `show` example program requires a newer compiler than 1.34.2 on
  some targets due to depending on `glium`. This is not considered a breaking
  bug.

## 0.15

Begin of changelog