cwltool/cwlrdf.py: Pass str rather than bytes to write function
cwltool/cwlrdf.py: Pass str rather than bytes to write function

Fix output of function in Python 3 runtime

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