Plemmy

See https://github.com/Fedihosting-Foundation/plemmy/pull/34 for details.

Thanks to Pdzly for the fix!

Implemented unit tests for:

- `LemmyHttp.login`
- `LemmyHttp.get_community`
- `LemmyHttp.create_post`
- `LemmyHttp.delete_post`
- `LemmyHttp.create_comment`
- `LemmyHttp.delete_comment`

Updates Plemmy to play nice with Lemmy `0.19.X` instances.

- `LemmyHttp` object now optionally accepts a `jwt` token on `__init__` if `LemmyHttp.login` method not called afterwards
- `jwt` token is no longer stored in the `LemmyHttp` object, it is passed directly to a `requests.Session` object
- `plemmy.utils.create_session` function accepts headers and `jwt` token, returns `requests.Session` object
- used in `LemmyHttp.__init__` and `LemmyHttp.login`
- `plemmy.utils.get_handler`, `plemmy.utils.post_handler`, and `plemmy.utils.put_handler` now accept a `requests.Session` object as their first arguments
- Updated all `LemmyHttp` methods to pass `requests.Session` object (`LemmyHttp._session` attribute) to updated `utils` functions

Bug fixes per issue https://github.com/LemmyWorld/plemmy/issues/26.

Thanks to Pdzly for finding this bug!

- Fixes/updates `LocalUser` attributes
- Remove extra comma

Thanks to Pdzly and deliciouslysmug for the contributions!

- Added new attributes to `CommentAggregates` and `PostAggregates` objects: https://github.com/tjkessler/plemmy/commit/c860f603d66e4e4d8d25e93290c99680356c5555
- Bug fixes: https://github.com/tjkessler/plemmy/commit/86a96c664e85d3aae842950f6d9c14ae6a0387d2