asciidoctor-epub3.gemspec in asciidoctor-epub3-1.5.0.alpha.19 vs asciidoctor-epub3.gemspec in asciidoctor-epub3-1.5.0

@@ -15,11 +15,11 @@
   s.authors = ['Dan Allen', 'Sarah White']
   s.email = '[e-mail]'
   s.homepage = 'https://github.com/asciidoctor/asciidoctor-epub3'
   s.license = 'MIT'
 
-  s.required_ruby_version = '>= 2.3.0'
+  s.required_ruby_version = '>= 2.4.0'
 
   files = begin
     (result = Open3.popen3('git ls-files -z') {|_, out| out.read }.split %(\0)).empty? ? Dir['**/*'] : result
   rescue
     Dir['**/*']
@@ -31,15 +31,15 @@
   s.require_paths = ['lib']
 
   s.add_development_dependency 'asciidoctor-diagram', '>= 1.5.0', '< 3.0.0'
   s.add_development_dependency 'asciimath', '~> 2.0'
   s.add_development_dependency 'coderay', '~> 1.1.0'
-  s.add_development_dependency 'pygments.rb', '~> 1.2.0'
+  s.add_development_dependency 'pygments.rb', '~> 2.2.0'
   s.add_development_dependency 'rake', '~> 13.0.0'
   s.add_development_dependency 'rouge', '~> 3.0'
-  s.add_development_dependency 'rspec', '~> 3.9.0'
+  s.add_development_dependency 'rspec', '~> 3.10.0'
   s.add_development_dependency 'rubocop', '~> 0.81.0'
-  s.add_development_dependency 'rubocop-rspec', '~> 1.38.0'
+  s.add_development_dependency 'rubocop-rspec', '~> 1.41.0'
 
   s.add_runtime_dependency 'asciidoctor', '>= 1.5.6', '< 3.0.0'
   s.add_runtime_dependency 'gepub', '~> 1.0.0'
   s.add_runtime_dependency 'mime-types', '~> 3.0'
 end