Fix Python packaging to use correct git log for package time/version stamps.
Fix Python packaging to use correct git log for package time/version stamps.

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