Aseg-gdf2

**Full Changelog**: https://github.com/kinverarity1/aseg_gdf2/compare/v0.6...v0.7

Fixed 31

What's Changed
* Change json_normalize update by kinverarity1 in https://github.com/kinverarity1/aseg_gdf2/pull/30


**Full Changelog**: https://github.com/kinverarity1/aseg_gdf2/compare/v0.5...v0.6

- Fix 19 (`GDF2(..., method='fixed-widths')` was broken)

- Add transparent support for using either pandas or dask to read the data table file
- Simplify field data API: `gdf.get_field_data()` and `gdf.get_fields_data()`

- Fix 16 - expanded column names not working in gdf2.df_chunked()