added error handling for when pwdSample fails to provide a suitable set of pairs
Revert "added error handling for when pwdSample fails to provide a suitable set of pairs"

This reverts commit e509000d7204cf02be4f115c3a3fb4b25a7f88e1.
added error handling for if pwdSample can't find any  pairs; reformatted script
switched to most active branch of gbm