Release 1.1.0

* Use built-in RDF.rb versions of vocabualries.
* All linting and entailment done using rdf-reasoner gem.
* Support schema:Role as property intermediary.
* Allow plain literal when rangeIncludes indicates an object.
* Be more descriptive when generating domain/range warnings, particularly when the resource is a BNode.
Release 1.1.1.

* Update for schema.org v1.8.
Update Gemfile.
Finish 1.1.1.1