Pdf2image

- Fixes version 1.12.0 on Windows
- Version 1.12.0 will no longer be available on PyPI

- Fix an exception that would occur whenever `convert_from_path` was used with multiple threads (but not multiple processes).

**This version was removed of PyPI as of 2020-02-17 since it introduces a deadlock on Windows**

- Add `jpegopt` option for finer control on output images quality when using `fmt='jpeg'` (Thank you abieler)
- Add public functions `pdfinfo_from_path` and `pdfinfo_from_bytes` which return a dictionary containing the parsed output of `pdfinfo`

- Add `paths_only=False` parameters, which returns images paths instead of image objects when set to true

- Add `size=None` parameter which uses either `-scale-to`, `-scale-to-x` or `-scale-to-y` in pdftoppm or pdftocairo
- `size=400` fits the image to a 400x400 pixels box, preserving aspect ratio
- `size=(400, None)` makes the image 400 pixels wide, preserving aspect ratio
- `size=(None, 400)` makes the image 400 pixels high, preserving aspect ratio
- `size=(400, 400)` makes the image 400 pixels by 400 pixels, not preserving aspect ratio

- **Drop support for python 2.7**
- Add generator for file names
- Add support for `pathlib.Path` objects