Ao3-api

Changes:

* Fixed `Work.get_bookmarks()`
* Added support for getting which collections a work belongs to and to add a work to one or many collections

Changes:

* Bug fixes
* Added more search options
* Added ability to comment or bookmark under a chosen pseud

Changes:
- You can now create and delete bookmarks using `Work.bookmark()` and `Work.delete_bookmark()` (and the same applies to series objects)

This version adds some bug fixes

Changes:
* Lots of bugfixes
* Added revised_at option to search
* Added `words` and `id` to metadata
* Added number of comments to Work metadata

Changes:
* `User.get_bookmarks`, `User.get_works`, `Search`, and `Series.work_list` now pull information from works without loading them
* Fixed issues 37, 38 and 39
* Completely changed `AO3.Comments`
* Added `AO3.Chapters`, a chapter endpoint part of an `AO3.Work`
* Added `Session.get_statistics`
* Minor fixes