expression.py: use unicode in constucting regex strings and pass explicit bytes to BytesIO
expression.py: use unicode in constucting regex strings and pass explicit bytes to BytesIO

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