cwltool/stdfsaccess.py: use io.open instead of builtin open
cwltool/stdfsaccess.py: use io.open instead of builtin open

common-workflow-language/cwltool,dleehr/cwltool,common-workflow-language/cwltool,common-workflow-language/cwltool,dleehr/cwltool,dleehr/cwltool,dleehr/cwltool