Simulate a cell lineage tree Adoped from https://github.com/elifesciences-publications/CRISPR_recorders_sims/blob/master/MATLAB_sims/GESTALT_30hr_1x_simulation.m
simulate_core(config, tree, mutation_site, outcome)
a `lineage_tree` object
simulation configuration; a lineage_tree_config object
a matrix representing the lineage tree
a binary matrix indicating the mutation sites
a character matrix