Added
- Added drop argument to several adder functions, giving the user the option to drop the original regressors after making certain transformations on them
Changed
- `add_ar_terms()` now accepts 0 as an argument but it doesn't do anything
Fixed
- fixed issue with `pop_using_criterion()` function that wasn't dropping models correctly in some instances
- fixed the default parameters for the rnn model which weren't working due to mislabeling of one of the parameters in TensorFlow. updated the docstring accordingly