v0.2.2

Major changes

• Implemented kfold() function to allow the estimation of ELPD to work with
  loo ecosystem
• Added simulated dataset for Emax model
  #7 (@djnavarro)

Minor changes

• Enable setting the prior distribution for linear models
• Added exp_candidates argument to extract_coef_exp_ci() function to allow
  for the extraction of coefficients from all candidate models
• Update package dependencies