Update spec metadata to pass common checks

[berezovskyi]

Axel sent a paper some time ago about F.A.I.R endpoints, which I was not particularly impressed by but recently I found a few tools to check our vocabs against:

http://linkeddata.uriburner.com:8000/vapour?uri=http%3A%2F%2Fopen-services.net%2Fns%2Fcore&acceptRdfXml=1&acceptTurtle=1&acceptJsonLD=1&validateRDF=1&htmlVersions=1&defaultResponse=dontmind&userAgent=http%3A%2F%2Flinkeddata.uriburner.com%3A8000%2Fvapour%23this#

• N3 conneg fail
• mixed q conneg fail
• first redirect shall not be 301 but 303
• the response does not contain a resource with the subject of the request URI

http://graphite.ecs.soton.ac.uk/checker/?uri=http%3A%2F%2Fopen-services.net%2Fns%2Fcore&output=html#

• RDDL prefix not recognized

https://labs.mondeca.com/parrot/parrot?&mimetype=default&profile=technical&language=en&documentUri=http://open-services.net/ns/core

• No results at all. Compare that blank screen to https://labs.mondeca.com/parrot/parrot?&mimetype=default&profile=technical&language=en&documentUri=http://www.w3.org/ns/shacl#

http://oops.linkeddata.es/response.jsp?uri=http://open-services.net/ns/core#

• Results for P38: No OWL ontology declaration.ontology* | Important Important
• Results for P39: Ambiguous namespace.ontology* | Critical Critical
• Results for P41: No license declared.

http://visualdataweb.de/webvowl/#iri=https://open-services.net/ns/core

• Quite empty due to lack of RDFS/OWL definitions

https://lov.linkeddata.es/dataset/lov/vocabs/oslc

• The information should be checked

[berezovskyi]

All relevant things are OK, for conneg issues opened oslc-op/website-content-negotiation#9