improved debugging for test_scripts.py
improved debugging for test_scripts.py

Winterflower/khmer,ged-lab/khmer,jas14/khmer,Winterflower/khmer,F1000Research/khmer,F1000Research/khmer,souravsingh/khmer,souravsingh/khmer,Winterflower/khmer,ged-lab/khmer,F1000Research/khmer,jas14/khmer,ged-lab/khmer,souravsingh/khmer,kdmurray91/khmer,kdmurray91/khmer,jas14/khmer,kdmurray91/khmer