squid.gemspec in squid-1.4.0 vs squid.gemspec in squid-1.4.1

@@ -11,10 +11,10 @@
   spec.summary       = %q{Generates graphs in PDF files.}
   spec.description   = %q{Squid expands Prawn providing method to easily draw graphs in PDF files.}
   spec.homepage      = 'https://github.com/fullscreen/squid'
   spec.license       = 'MIT'
 
-  spec.required_ruby_version = '>= 2.1.0' # 2.0 does not have Numeric#step(by:, to:)
+  spec.required_ruby_version = '>= 2.2.0' # support for 2.1 has ended
 
   spec.files         = `git ls-files -z`.split("\x0").reject { |f| f.match(%r{^(test|spec|features)/}) }
   spec.bindir        = 'exe'
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']