info stops schema descent on "traversable" node

[braingram]

Description of the problem

_node_info collection stops descending into a schema if the node is "traversable" (has __asdf_traverse__).

asdf/asdf/_node_info.py

Lines 276 to 277 in a866c98

	if parent.schema is not None and not cls.traversable(node):
	info.set_schema_for_property(parent, identifier)

even if the parent has a non-None schema. This seems incorrect as a node with __asdf_traverse__ may have a valid subschema.

Example of the problem

None yet...

System information

asdf version:
python version:
operating system: