updated tests/test_streaming_io.py to work with khmer installs
updated tests/test_streaming_io.py to work with khmer installs

ged-lab/khmer,F1000Research/khmer,ged-lab/khmer,souravsingh/khmer,ged-lab/khmer,F1000Research/khmer,souravsingh/khmer,souravsingh/khmer,F1000Research/khmer