Bayes factors for association between paired samples, using one of Pearson's product moment correlation coefficient, or Kendall's tau. Spearman's rho to be implemented. For technical details see Ly, Marsman and Wagenmakers (2018) "Analytic posteriors for Pearson's Correlation Coefficient" <doi:10.1111/stan.12111> and van Doorn, Ly, Marsman, Wagenmakers (2018). "Bayesian inference for Kendall’s rank correlation coefficient". <doi:10.1080/00031305.2016.1264998>