pathname bug

[rwst]

In [1]: import sys 
   ...: from pyshexc.parser_impl.generate_shexj import generate 
   ...:  
   ...: generate(['shexset/molbio/E37'])                                                               
RDFLib Version: 5.0.0
ANTLR runtime and generated code versions disagree: 4.9!=4.7.2
ANTLR runtime and generated code versions disagree: 4.9!=4.7.2
JSON output written to shexset/molbioE37.json
turtle output written to shexset/molbioE37.ttl

PR in preparation.