The flag --allow-infos should be forward-ported to case_validate

[ajnelson-nist]

pySHACL PR 121 added a flag --allow-info (and --allow-infos) to pyshacl. case_validate was supposed to pick this up, but it was apparently forgotten.

UCO Issue 430 raises sh:Info-severity notes that have some reason to be ignored when UCO is used to annotate nodes that operate in the classic-RDF "Treat this URL as an rdfs:Resource" pattern.

case_validate should pick up the --allow-infos flag.