dnase_bias_estimator.py argument names

[hughes-drew]

Hi Jason,

Thanks for putting together these excellent tools and making them so accessible. I've just downloaded pyDNase. When attempting to run dnase_bias_estimator.py I get a "namespace has no attribute genomesize" error. I believe the argument variable name is stored as "genomesize" (line 89) and then referred to as "genome_size" (line 96).

Best,

Drew

[jpiper]

Thanks for this! Fixing in #17