v1.2.0

• Added LineSpecModel for fitting integrated emission line fluxes (h/t @kgarofali).
• Add AGNSpecModel with a scalable, empirical AGN emission line template.
• Fix floating point issue with Dirichlet SFH transforms (h/t TakumiSTanaka)
• Implement nested_target_n_effective as dynesty stopping criterion.
• Fixes to the dynesty interface for dynesty >= 2.0 (h/t mjastro)
• Fix sign error in Powell minimization (h/t blanton144)
• Fix bugs in parameter template for emission line fitting.
• numerous documentation updates including nebular emission treatments.