v0.4.0

Added

• add multi-objective scores, constrained dominance and non-dominated sorting (#58)
• add the multi-objective engine and NSGA-II (#60)
• add multi-objective indicators: hypervolume, IGD, IGD+, GD and spread (#62)
• add a Pareto archive of non-dominated solutions (#64)
• add the ZDT and DTLZ test problems and Das-Dennis reference points (#66)
• add NSGA-III with reference directions (#68)
• add SPEA2, the strength Pareto evolutionary algorithm 2 (#72)
• add MOEA/D with Tchebycheff and PBI decomposition (#74)
• add SMS-EMOA and exclusive hypervolume contributions (#76)

Fixed

• [breaking] mutate each gene independently at the per-gene rate (#70)

Documentation

• benchmark multi-objective algorithms against pymoo and DEAP (#77)