Summary

This branch improves error handling on IV functions, especially in relation to predictors in which their p-values fall below the required significance level set at siglevel. A new argument exc_sig has been added.

Changes

The changes made in this PR are:

1. Added argument exc_sig to create_IV()
2. Added error message if no predictors are left after predictors have been filtered out.

Checks

• All R CMD checks pass
• roxygen2::roxygenise() has been run prior to merging to ensure that .Rd and NAMESPACE files are up to date.
• NEWS.md has been updated.