Allow jsonldPredicate to be a str
Allow jsonldPredicate to be a str

Fix https://github.com/common-workflow-language/schema_salad/issues/418 .

common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad,common-workflow-language/schema_salad