New observables: Higgs production and decay, beta decays, e⁺e^- scattering, kaon and pion decays This release adds a large number of new observables that have been recently implemented in flavio 2.0 (based on arXiv:1911.07866 by Adam Falkowski and David Straub and a collaboration of Martín Gonzalez-Alonso, Adam Falkowski, and David Straub): 32 new observables in the likelihood fast_likelihood_quarks.yaml: kaon decays, pion decays, nuclear and neutron beta decays, 48 observables in the new likelihood likelihood_eeww.yaml: total and differential cross sections of e⁺e^-→W⁺W^-, 33 observables in the new likelihood likelihood_higgs.yaml: Higgs signal strengths. This raises the total number of observables taken into account in the global likelihood to 399. New feature The CKM scheme used by a GlobalLikelihood instance can now be selected on instantiation using the optional argument ckm_scheme. This will facilitate the use of different CKM schemes in the future (currently, only one default CKM scheme is defined). Bugs fixed Removed the branching ratio of Λ_b→Λμμ in the [1.1, 6] GeV² bin. If a GlobalLikelihood instance is created with the argument fix_ckm=True, now the default CKM elements from flavio are used instead of those defined by the default CKM scheme. Other updates The required flavio version is now v2.0. The flavio version is not pinned anymore to allow updating flavio from pip before updating smelli.