grom.gemspec in grom-0.3.10.pre vs grom.gemspec in grom-0.4.0

@@ -20,9 +20,11 @@
   spec.bindir        = 'exe'
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 
   spec.add_dependency 'rdf', '2.2.3'
+  # Defines RDF vocabularies
+  spec.add_dependency 'rdf-vocab', '~> 2.2'
   spec.add_dependency 'activesupport', '>= 5.0.0.1'
 
   # the below are test dependencies
   spec.add_development_dependency 'bundler', '~> 1.13'
   spec.add_development_dependency 'rake', '~> 10.0'