fix merge problem (put remove_cols functionality back into new_builder.Contribution)
fix merge problem (put remove_cols functionality back into new_builder.Contribution)

Caoimhinmg/PmagPy,Caoimhinmg/PmagPy,lfairchild/PmagPy,lfairchild/PmagPy,Caoimhinmg/PmagPy,lfairchild/PmagPy