Heroku-18 Support
- Updates binary to support Heroku-18 stack (wkthmltopdf 0.12.5), thanks @gregnavis for providing the file.
Older stacks (e.g. heroku-16) will need to use version 2.12.4.0.
Older stacks (e.g. heroku-16) will need to use version 2.12.4.0.