Fix SQLAlchemy column detection when saving to YAML
Fix SQLAlchemy column detection when saving to YAML

[1] added some "relationship" fields to the SQLAlchemy definition of
some classes. This broke the way columns are detected in the saveYAML()
and saveYAML_commit() functions, and extra fields were included in the
YAML output, breaking commit import.

This commit fixes that by using a different method to detect the columns
in a SQLAlchemy object.

[1] - https://softwarefactory-project.io/r/c/DLRN/+/19976

Change-Id: Ib44c02eb766426faeb65d0d9d5c20bfe5d7e11d9

openstack-packages/delorean,openstack-packages/delorean