Tastytrade

New release with substantial changes to the streamer, including the new dxlink streamer.

Features
* Streamer update for the new DXFeed API by Quenos in https://github.com/tastyware/tastytrade/pull/83
* Documentation updated by Mytak in https://github.com/tastyware/tastytrade/pull/85
* pytest by Graeme22 in https://github.com/tastyware/tastytrade/pull/94
* add extensive tests (cert session only); coverage >95 enforced by Graeme22 in https://github.com/tastyware/tastytrade/pull/99
* Update streamer.py by Quenos in https://github.com/tastyware/tastytrade/pull/103
* streamers use async context managers; prod session in testing by Graeme22 in https://github.com/tastyware/tastytrade/pull/104

Bugfixes
* Attributes made optional in class MarketMetricInfo(TastytradeJsonDataclass) by Quenos in https://github.com/tastyware/tastytrade/pull/78
* Optional market metrics by Mytak in https://github.com/tastyware/tastytrade/pull/80
* Datatypes changed by Mytak in https://github.com/tastyware/tastytrade/pull/86
* enhanced-fraud-safeguards-enabled-at fix by MaxxRK in https://github.com/tastyware/tastytrade/pull/90

New Contributors
* Quenos made their first contribution in https://github.com/tastyware/tastytrade/pull/78
* Mytak made their first contribution in https://github.com/tastyware/tastytrade/pull/80

**Full Changelog**: https://github.com/tastyware/tastytrade/compare/v6.1...v7.0

New major release!

**Breaking changes**:
- streamer overhaul: you must now call `listen` with a specific event type.
- session is now an abstract class; you must create a `CertificationSession` or `ProductionSession`, which have different functionalities.

**New features**:
- less repetitive imports: certain objects, like `Account`, `DataStreamer`, and `ProductionSession`, can now be directly imported from the `tastytrade` module.
- new dxfeed REST API allows instances of `ProductionSession` to fetch events in a simpler way, bypassing the streamer
- `Underlying` is now a supported event type for the streamer and the REST API
- new docs sections for installation, sessions and streamer; more coming soon!

**Bugfixes/other**:
- fix incorrect return type for `AccountBalance` 72
- update certification accounts, which no longer can instantiate a streamer 73
- CI now checks a range of recent Python versions instead of just one
- fix illegal ABC implementation 74

A bugfix release with a couple new features:

- `MarketMetricInfo` handles optional attribute (66)
- `Future` handles optional attributes (65)
- Refactor to enforce flake8 line length rule E501
- Fix failing docs build due to pydantic v2 release
- Add ETH as a funding method
- Add risk free rate (64)

Streamer bugfix/simplification

fix critical streamer bug; other small fixes

New features: 50