Path parameters don't preserve description

[fmigneault]

When using definition of an endpoint like so:

class MyValue(MappingSchema):
    value_id = SchemaNode(String(), description='My precious value')

Corresponding to following service and method:

myvalue_service = Service(name='myvalue', path='/values/{value_id}')

@myvalue_service.get(schema=MyValue())
def get_my_value(request):
    value_key = request.matchdict.get('value_id')
    return value_dict[value_key]

The parameters section of the returned swagger json for GET /values/{value_id} doesn't preserve the description ('My precious value') for value_id. The parameter is listed, but just doesn't have its description (maybe also example? not tested).

Other descriptions for querystring and body elements are properly preserved using the same description input, but not for path elements.