Release 3.3.1

Depend on Rack ~> 3.1 instead of 2.2.

Release 3.3.0

Updates for version 3.3.0 with minumum Ruby version 3.0.

Release 3.2.3

Relax dependency on rack and rack-test.

Release 3.2.0

• Minimum Ruby version now 2.6.

Release 3.1.2

'rdf',        '~> 3.1', '>= 3.1.15'
'rack',       '~> 2.2'

Release 3.1.1

• Improve documentation.
• Update dependency for RDF.rb to 3.1.8.

Release 3.1.0

Based on rack-linkeddata.