py3 compatibility: modified url2pathname acoordingly
py3 compatibility: modified url2pathname acoordingly

common-workflow-language/schema_salad,manu-chroma/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,manu-chroma/schema_salad