Reasoner-pydantic

What's Changed
* Hashable Models in https://github.com/TranslatorSRI/reasoner-pydantic/pull/19
* Add update method in https://github.com/TranslatorSRI/reasoner-pydantic/pull/22

**Full Changelog**: https://github.com/TranslatorSRI/reasoner-pydantic/compare/v1.2.0.4...v2.0.0

Fixes:
* correct constraints default to []

Fixes:
* require pydantic>=1.8
* add missing operations

Fixes:
* MetaKnowledgeGraph `nodes` and `edges` are required, but `edges` may be empty

Bug fixes:
* Convert `negated` to `not` in `.dict()` even without `by_alias=True` - this is necessary for FastAPI to generate `Responses`
* Point `Query`, etc. to the correct Workflow
* Make `Operation` ids strings
* Remove standards.ncats.io `$refs` - these are not necessary for _equivalence_ of the schema with TRAPI, and were causing issues in Swagger UI