Add license to ontology header

[cmungall]

http://obo-dashboard-test.ontodev.com/ - the ontology is failing the 'open' check

the release owl should contain:

     xmlns:terms="http://purl.org/dc/terms/"
...
        <terms:license rdf:resource="https://creativecommons.org/publicdomain/zero/1.0/"/>

See https://github.com/OBOFoundry/OBOFoundry.github.io/issues/1041

[diatomsRcool]

I think I fixed this, but I'll wait to see if the obo dashboard updates before closing this issue.

[matentzn]

https://github.com/EnvironmentOntology/environmental-exposure-ontology/pull/121#issuecomment-689701495

[matentzn]

Sorry Anne!

[diatomsRcool]

It's still failing on the OBO dashboard. Not sure what's going on.

[matentzn]

your obo markdown file has a different license!!

[diatomsRcool]

https://github.com/OBOFoundry/OBOFoundry.github.io/pull/1447