SurrogateRsq v0.2.1

Minor improvements and fixes

• The data argument is removed from all three main functions surr_rsq(), surr_rsq_ci(), and surr_rsq_rank(). The dataset will be directly pulled our from the full_model object.

• The bug related to the bootstrapped data and the model updating steps in surr_rsq_ci() have been fixed (#2, #3).

• rsq() function is removed since it is no needed.