Depend on sinatra ~> 4.0 rather than 3.1.

Author: gkellogg

sparql.gemspec

@@ -41,8 +41,8 @@ Gem::Specification.new do |gem|
 
   gem.add_development_dependency 'getoptlong',         '~> 0.2'
   gem.add_development_dependency 'ostruct',            '~> 0.6'
-  gem.add_development_dependency 'sinatra',            '~> 3.1'
-  gem.add_development_dependency 'rack',               '>= 2.2', '< 4'
+  gem.add_development_dependency 'sinatra',            '~> 4.0'
+  gem.add_development_dependency 'rack',               '~> 3.1'
   gem.add_development_dependency 'rack-test',          '~> 2.1'
   gem.add_development_dependency 'rdf-spec',           '~> 3.3'
   gem.add_development_dependency 'linkeddata'