- Use [Black](https://github.com/psf/black) code formatting in source
1.7.0
- Add `grayscale` parameter which allows you to convert images to grayscale
1.6.0
- Add `single_page` parameter which allows you to convert the first PDF page only, without adding digits at the end of the `output_file` - Fix simplistic name matching that would sometime fail when `output_file` was contained in the name of another file or directory of the `output_folder`
1.5.4
- Fix `first_page` greater than `last_page` throwing error. From now on it will return an empty list
1.5.3
- Minor bugfix for `poppler_path` which would not find libpoppler on Linux.