implemented @BoyerWOD suggestions for WOD_gradient_check.py
implemented @BoyerWOD suggestions for WOD_gradient_check.py

IQuOD/AutoQC,s-good/AutoQC,s-good/AutoQC,castelao/AutoQC,BillMills/AutoQC,IQuOD/AutoQC,BillMills/AutoQC