[data-shapes] publish `shacl-test` ontology (#270)

VladimirAlexiev has just created a new issue for https://github.com/w3c/data-shapes:

== publish `shacl-test` ontology ==
Related to https://github.com/w3c/data-shapes/issues/269 : 
SHACL tests use terms from this namespace:
```ttl
@prefix sht: <http://www.w3.org/ns/shacl-test#>
```

However, it does not resolve, and I suspect the respective ontology file needs to be created too.

Please view or discuss this issue at https://github.com/w3c/data-shapes/issues/270 using your GitHub account


-- 
Sent via github-notify-ml as configured in https://github.com/w3c/github-notify-ml-config