predint 1.1.1

predint 1.1.1

• Argument for the tolerance in the bisection
• Small changes in the readme
• Bugfix in beta_bin_pi
• Changed lambda_min and lambda_max to delta_min and delta_max in order
  to reflect the notation of the manuscript submitted to JSS
• Bugfix in rbbinom: rho must be bigger than 0 but smaller than 1
• Function for the sampling of bs-data based on a random effects model fit with lme4::lmer()
  as used in lmer_pi_futmat()