Multporn

* Removed `RequestHandler` class
* Added `requestsParams` argument to all three classes
* Added proxy support to all three classes
* Files now are only skipped for error code `404`

**Full Changelog**: https://github.com/pyporn-san/Multporn/compare/v1.3.6...v1.4.0

Change in requirements.txt that stops this package breaking installs for no good reason

* Fixed return in `Multporn.downloadContent()`

* Fixed and optimized `Multporn.downloadContent`

* **Finally** added documentation
* increased the python version requirement to 3.8 because of `cached_property` not existing in older versions