Adding SoyBase Xrefs to TO terms

[cooperl09]

Following up from the discussion at the AgBioData Ontology WG meeting: Adding SoyBase Xrefs to TO terms with @maxglycine

Be sure to use the most recent version of the editors file from GitHub: https://github.com/Planteome/plant-trait-ontology/blob/master/plant-trait-ontology.obo
You can edit it in either your favorite text editor or in Protege.
Please follow the pattern in the PO, add the SOY term name as a related synonym, and attach the Dbx ref to the synonym