- Several small fixes in the retrieval framework (thanks wbalmer!)
- Added `flux_units` parameter to `get_mcmc_photometry`
- Support for fitting multiple `disk_teff` and `disk_radius` parameters in `FitModel`
- Support for fitting the combined photometry of unresolved binary stars with different parallaxes
- Multiple improvements for fitting a combination of two spectra in `FitModel`
- Support for flux ratio prior for filters when fitting a binary system
- Check for NaNs in the uncertainties when adding a spectrum with `add_object`
- Updated `plot_posterior` for showing posteriors from binary systems
- Returning the individual binary components with `get_mcmc_spectra`
- Added support for coolTLUSTY Y dwarf spectra
- Tutorial for comparing data with a model grid of spectra
- Support for fitting separate `ism_ext` parameters for a binary system
- Support for PHOENIX Husser et al. (2013) models
- Major refactoring of `FitModel`, improved extinction accuracy, faster interpolation based on Teff prior
- Added optional `database_file` parameter to `SpeciesInit`
- Added `fixed_param` parameter to `add_samples`
- Added `tag` parameter and several improvements in `get_residuals`
- Changed the values added with `inc_loglike` to ln(L)
- Included chi2 and n_dof in `ResidualBox`
- Fixed indentation problem in `CompareSpectra`
- Robust implementation for filenames by using the `pathlib` instead of the `os` module
- Using `pooch` instead of `urllib` for downloading files
- Fixed bug in `get_samples` with reading normal priors
- Fixed bug with storing the log-likelihood after running `run_multinest`
- Fixed Windows issue with the Linder et al. (2019) isochrones
- Check for NaN and inf when calculating the goodness-of-fit statistic in CompareSpectra
- Exclude SpeX spectra that can not be flux calibrated when adding with `add_spectra`
- Updated dependency versions
- Overall code maintenance, many minor improvements, and updated tutorials