1.2.0

This was a long put off maintenance upgrade that added

1. Tests
2. Uses pydantic for schema validation instead of my special custom stuff
3. Brings room and message event type support up to matrix 1.15 spec

Users should see no degradation unless they rely on the _raw internal object endpoints. Either use the newly supported event types (if an old one was missing), or configure pydantic to be lax via the new security config flag