**Core Changes**
- Replaced `assert` statements in *frameguard.py* with `if` statements
- Changed default file extension for `FrameGuard.export_schema()` to *.yml*
- Removed `FrameGuard._check_features()` static method and replaced logic
- Updated *tests\test_frameguard.py* and added *tests\test_schema.yml*
- Updated documentation (*README.md*)
**API Changes**
- Renamed `d_type`, `minimum` and `maximum` constraints to `data_type`, `min` and `max`, respectively
- Renamed `FrameGuard.update_schema()` to `FrameGuard.add_constraint()`
- Renamed `FrameGuard.load_schema()` to `FrameGuard.import_schema()`
- Renamed `FrameGuard.save_schema()` to `FrameGuard.export_schema()`