fixed failing test to ignore first k bases in read in error profile
fixed failing test to ignore first k bases in read in error profile

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