Tc-pdf

What's Changed
* Provide Thumbor 7 / Python 3 compatibility by relthyg in https://github.com/intellisense/tc_pdf/pull/3

New Contributors
* relthyg made their first contribution in https://github.com/intellisense/tc_pdf/pull/3

**Full Changelog**: https://github.com/intellisense/tc_pdf/compare/0.0.7...1.0.0

- Use tornado async http client to prevent `create_preview` coroutine from locking the tornado loop
- Patch request and context only after preview is successfully created or fetched from storage

- Set preview file name in response headers instead of pdf file name

- Major bug fix, should not use previous versions
- [Fixed](https://github.com/intellisense/tc_pdf/commit/0c1b08c888700e710a346b1679a73d0af6c82e05) app registration in `__init__`