species v0.5.0

• Framework for free retrievals with petitRADTRANS in the AtmosphericRetrieval class
• Notebook tutorials for free retrievals and reading companion data
• Changed the co parameter to c_o_ratio
• Added list_filters method to ReadObject
• Support for fitting blended stars/companions with FitModel
• Photometric error inflation per instrument
• Added synthetic_photometry method to ModelBox
• Possibility to show a plot instead of writing to a file
• Refactoring of add_model
• Support for Sonora model spectra
• Added available_models to Database for details about the atmospheric models
• Added reduced chi2 calculation to get_residuals
• Added get_evidence method to Database
• Added support for Python 3.10 and removed support for Python 3.7
• Updated documentation, docstrings, and dependency versions
• Many small new features, enhancements, and bug fixes!