Make default saving option relative
Make default saving option relative

Saving workflows with wd=True only works when you use a working dir.
Since this is optional, it makes more sense to use relative paths
(and assume the user uses the nlppln CWL_PATH to save their workflows).

WhatWorksWhenForWhom/nlppln,WhatWorksWhenForWhom/nlppln,WhatWorksWhenForWhom/nlppln