Implement this sampler, which is an ensemble Metropolis method. * Braak, C.J.T., 2006. [A Markov Chain Monte Carlo version of the genetic algorithm Differential Evolution: easy Bayesian computing for real parameter spaces](http://stat.columbia.edu/~gelman/stuff_for_blog/cajo.pdf). Statistics and Computing, 16, pp.239-249.
Implement this sampler, which is an ensemble Metropolis method.