Add --print-supported-versions option
Add --print-supported-versions option

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